Public health is what we, as a society do collectively to assure the conditions for people to be healthy.
—IOM, 1988, p. 19
Pain can be conceptualized as a public health challenge for a number of important reasons having to do with prevalence, seriousness, disparities, vulnerable populations, the utility of population health strategies, and the importance of prevention at both the population and individual levels.
First is the extent of the problem: pain affects tens of millions of Americans and contributes substantially to morbidity, mortality, disability, demands on the health care system, and significant economic burdens for the nation. The prevalence of chronic pain is growing and likely to continue to do so. (See Chapter 1.)
Second, there are substantial disparities in pain prevalence and seriousness and rates of undertreatment across population groups. Inadequately treated pain is more common in vulnerable populations—including the elderly, children, racial and ethnic minorities, and others—that are a traditional concern of public health agencies and programs.
Third, because pain is ubiquitous across the population, imposes a differential burden on vulnerable subgroups, and is affected by conditions in the social, physical, and economic environments, a comprehensive pain prevention and
management strategy at the population health level is needed. It is not sufficient to treat pain merely on a case-by-case basis in physicians’ offices and other health care settings.
Fourth, pain is costly to the nation—not just in terms of health care expenditures and disability compensation but also in terms of lost school days, lost productivity and employment, reduced incomes, and, indeed, lost potential and quality of life.
Fifth, pain raises societal issues that extend beyond individuals and their suffering. Specifically, the opioid medications that are effective for many people with pain also are subject to misuse and abuse, and ensuring that they are available for those who need them and not available to abusers necessitates cross-governmental efforts at all levels.
Sixth, the public’s health is greatly influenced by the graduates of the nation’s health professions training programs, many of which are heavily supported with public monies. From initial education through continuing education programs, health professionals need to learn more about the importance of pain prevention, ways to prevent the transition from acute to chronic pain, how to treat pain more effectively and cost-effectively, and how to prevent other physical and psychological conditions associated with pain.
Seventh, the ability to reduce pain’s impact on the public’s health can be strengthened as a result of new knowledge generated by the nation’s vital research establishment through basic, clinical, and translational research; epidemiologic studies; and analysis of care patterns and costs.
Finally, public health offers an infrastructure and a forum for developing strategies for preventing and addressing pain. Multiple federal agencies—such as the Centers for Disease Control and Prevention (CDC), Food and Drug Administration (FDA), National Institutes of Health, Agency for Healthcare Research and Quality (AHRQ), Surgeon General, and Departments of Veterans Affairs and Defense—can interact with state and local public health agencies and private-sector partners to develop and implement public education efforts and other population-based interventions.
The Department of Health and Human Services’ (HHS) vision and strategic framework on multiple chronic conditions is an example of a multipronged effort to accomplish much of what a coordinated national initiative on pain might do (HHS, 2010b). The starting point for the HHS initiative was recognition of the high human and economic costs of multiple chronic diseases, many of which include a substantial pain component. Problems that result from having several chronic diseases mirror in many ways the challenges experienced by people with severe chronic pain: “poor functional status, unnecessary hospitalizations, adverse drug events, duplicative tests, and conflicting medical advice” (HHS, 2010b, p. 2). The kind of systems thinking and stakeholder involvement that went into the HHS strategic framework parallels what the public health community could accomplish in pain care.
This is not to say that the committee believes pain management services should be the sole responsibility of any one public health entity or of public health personnel. Instead, the committee acknowledges the understanding promulgated in The Future of the Public’s Health in the 21st Century that a contemporary public health system calls for “the contributions of other sectors of society that have enormous power to influence health” (IOM, 2002a, p. 2). With respect to improving pain management, those sectors include
- the health care delivery system, for pain prevention, assessment, treatment, and follow-up;
- health professions educational institutions, for improvements in education, mentoring, and modeling of good pain care;
- businesses and employers, which influence group health insurance coverage policies;
- the research establishment, for stimulating new understandings of pain that may lead to prevention, early intervention, and new treatments that are more effective and less problematic;
- state and federal policy makers, who must craft policies related to patient safety, dispensing of opioid drugs, regulation of clinicians’ scope of practice, workers’ compensation programs, drug marketing, insurance coverage of pain services, and many others;
- voluntary health organizations, especially those consumer-oriented groups devoted to pain conditions, but also groups for which pain is a significant problem for their primary constituents, such as the American Cancer Society, the American Diabetes Association, the National Alliance on Mental Illness, and many others;
- the pharmaceutical and device industries, as they attempt to develop new, more effective, and more targeted analgesics;
- accrediting and licensing bodies, which set the educational and practice standards for clinicians; and
- the news and information media, which can affect public opinion and increase understanding of acute and chronic pain.
The variety of entities potentially involved in a broad-based effort to improve pain prevention and management across U.S. society offers promising opportunities for the kinds of public–private partnerships envisioned in the charge to this committee (see Chapter 1).
Recently released goals and objectives for Healthy People 2020—“the health agenda for the nation,” issued by HHS—appear to anticipate a larger public health role in pain management. Under the Medical Product Safety topic is a new objective—“Increase the safe and effective treatment of pain”—although this objective does not explicitly frame a comprehensive or strategic approach to pain, and three of its four subparts remain under development (Box 2-1).
Healthy People 2020 Pain Relief Objectives
Medical Product Safety (MPS) Objective 2: Increase the safe and effective treatment of pain
|MPS 2.1||Reduce the proportion of patients suffering from untreated pain due to a lack of access to pain treatment|
|MPS 2.2||Reduce the number of nonFDAapproved pain medications*|
|MPS 2.3||Reduce serious injuries from the use of pain medicines|
|MPS 2.4||Reduce deaths from the use of pain medicines|
*This is the only objective that, as of Healthy People’s December 2010 release, was not considered “developmental”; however, the committee was unable to obtain a list of non-FDA-approved pain medications from the FDA.
Medical Product Safety Objective 2.2—“Reduce the number of non-FDA-approved pain medications”—needs additional clarification. The intent of this objective is not to address “off-label” uses of drugs for pain,1 but to focus on drugs whose use predated current strict FDA oversight and that the FDA has never approved. The committee was unable to obtain a list of these drugs from the FDA and believes that decisions to withdraw specific medications could have unintended consequences that would be detrimental to patients. Therefore, such decisions should be evidence based, transparent, and made in consultation with clinicians who treat people with pain.
Only two other Healthy People 2020 objectives relate to pain. One focuses on reducing disability from arthritis and the other on reducing nonmedical use of prescription drugs, including pain relievers (HHS, 2010a).
Pain—especially severe, chronic pain—interferes with multiple aspects of the individual’s life and has many consequences. The remainder of this chapter begins by summarizing data from national surveys, as well as independent research studies, to provide insight into the large number of people with pain
1 Many FDA-approved medications are used for pain “off-label” (that is, they are approved drugs, but not approved specifically for pain or approved only in specified doses), and these constitute a significant share of clinicians’ pain care resources, especially for children and the elderly, groups usually omitted in clinical trials. Off-label use of prescription drugs, in general, is common; an estimated 21 percent of office-based physicians’ overall use of commonly prescribed drugs is off-label (Radley et al., 2006). Examples of drugs used off-label for pain care are antiseizure drugs used for migraine and nerve pain, antidepressants for chronic pain, beta-blockers for migraine, and opioids for people with only mild or infrequent pain (Consumers Union, 2007).
conditions and the differential impacts of pain on various population groups. The chapter then examines the seriousness of pain by describing its effects on daily activities, productivity, and quality of life, as well as its link with suicide; this section also includes a discussion of differences in the seriousness of pain by race/ethnicity and sex. Finally, the chapter reviews data on the financial costs of pain and its treatment before turning to a discussion of an expanded focus on public health’s role in pain prevention and treatment.
I have been told to “suck it up”; I have been asked if I was having trouble at home; I have been accused of being a “druggy” (drug seeking female). I have also found some practitioners who could “read the tea leaves,” so to speak, and TELL ME how much pain I must be in, based on my physical exam.
—A person with chronic pain2
Neuropathic pain has reached an epidemic. More than 6 million Americans have unrelenting nerve pain. Now it will increase tremendously because of the epidemic of diabetes.
—Tina Tockarshewsky, The Neuropathy Association, an advocate for people with chronic pain3
Data Sources and Limitations
Obtaining a definitive picture of the extent and significance of pain is difficult. Current data on the incidence, prevalence, and consequences of pain are not consistent or complete, in part because in many cases pain is treated as a symptom, and what is collected is data on underlying conditions or events (see Box 2-2). For example, data on health care utilization are organized by diagnoses (e.g., arthritis or spinal disorders), but the extent to which the pain of these conditions drove people to the health care system is unclear. Similarly,
2 Quotation from response to committee survey.
3 Quotation from oral testimony to the committee, November 2010.
Key Shortcomings of Data on Pain Prevalence in the United States
- There is no standardization of methods, definitions, and survey questions regarding pain used in population-based studies across and within agencies.
- Existing international standards for questions on some aspects of pain (e.g., low back pain) are not used by U.S. population-based health surveys, hindering cross-national comparisons.
- National populationbased health surveys usually do not include people in the military or those living in nursing homes, chronic care facilities, or corrections facilities.
- In most cases, painrelated questions in national populationbased health surveys are asked only of adults.
- Available data relate to only a few conditions (e.g., arthritis, low back pain).
- General items on pain (e.g., pain in the last month) do not describe types of pain.
- Acute and chronic pain are not distinguished in available data.
- Longitudinal data on consequences of pain are not available, and the data often are old.
- Complete data for population subgroups are unavailable because of these weaknesses (although some differences among subgroups—women, American Indians, those with lower levels of education or income—appear clear).
the reason for a physician visit is recorded as, for example, “knee symptoms” or “back symptoms,” and while some or all of these visits may have been prompted by pain, it is impossible to know. In constructing the picture of pain provided in this chapter, the committee could not rely solely on large epidemiologic studies or clinical trials. Such data simply are not available to describe the full impact of pain from different causes, in different population groups, or with different impacts. Instead, the committee assembled a variety of types of data from different types of sources that, taken together, suggest the broad outlines of the problem.
Furthermore, data on pain from different U.S. federal sources often do not agree. They are based on different survey questions and methodologies; some sources rely solely on self-report, while others also check medical records. Seeking insights from cross-national studies can be helpful, but the possibility of cultural differences in pain expression and expectations of treatment cannot be ignored, nor can differences in data collection methods that could affect comparisons. Moreover, since chronic pain in particular has a lengthy trajectory, longitudinal data on its consequences—medical, financial, social, and otherwise—would be a valuable resource, but these data are not available. As a result of such limita-
tions, the profile in this chapter cannot be said to be complete, but rather strongly suggestive of the dimensions of pain in the United States.
The major sources of U.S. population health data including information on pain are two large, ongoing surveys conducted by the National Center for Health Statistics (NCHS), an agency within CDC. The first is the National Health Interview Survey (NHIS), an ongoing, cross-sectional household interview survey of approximately 35,000 U.S. households collectively containing about 87,500 persons. It is large enough to enable analysis of health information for many demographic and socioeconomic groups. The second is the National Health and Nutrition Examination Survey (NHANES), which collects data through in-person interviews and physical examinations of a representative sample of about 5,000 Americans annually. The NHANES includes demographic, socioeconomic, dietary, and health-related questions; medical, dental, and physiological measurements; and laboratory tests.
Data from national population-based surveys such as the NHIS are very limited in scope. For example, arthritis and pain questions included in the NHIS 2009 adult questionnaire were restricted to eight pain sites, asked about pain during the past 30 days, and did not distinguish between acute and chronic or persistent pain or among types of arthritis (e.g., rheumatoid arthritis, gout). Patterns in the prevalence of these pain conditions based on the NHIS questions may not reflect differences in levels of activity limitation, quality of life, or access to appropriate pain care. Most important, pain-related conditions such as lupus, sickle-cell disease, ankylosing spondylitis, and other conditions may not be captured in these data.
Moreover, both the NHIS and the NHANES use samples of civilian, noninstitutionalized populations. They do not include people with chronic pain who are in the military or live in corrections facilities, nursing homes, or other chronic care facilities.
In addition to the NHIS and NHANES, the Medical Expenditure Panel Survey (MEPS), a project of AHRQ, surveys U.S. families and individuals, their medical providers (doctors, hospitals, pharmacies, etc.), and employers. The MEPS collects data on the use of health services, their costs, how they are paid for, and health insurance coverage. Pain data are obtained from both self-reports and providers’ reports. Given the limitations of and the very high-level picture provided by these national data sets, this chapter includes findings from a large number of smaller-scale, independent studies in an attempt to round out the picture of pain and its effects.
The most prominent feature of pain that qualifies it as a public health problem is its sheer prevalence, as well as its apparent increase (discussed in the next section). Of course, estimates of the current prevalence of pain in a population vary depending on the definitions and methods used. Nevertheless, an interna-
TABLE 2-1 Age-Adjusted Rates of U.S. Adults Reporting Pain in the Last 3 Months, Selected Causes, 2009
|Cause of Pain||U.S. Average, Adults 18 and Over (%)|
|Severe headache or migraine||16.1|
|Low back pain||28.1|
SOURCE: CDC and NCHS, 2010.
tional group of researchers using the World Health Organization’s (WHO) World Mental Health Survey instrument in 10 developed countries has estimated that some 37 percent of adults in these populations (age-standardized) have common chronic pain conditions (Tsang et al., 2008). In the United States, the prevalence rose to 43 percent, amounting to approximately 100 million adults in 2010—a conservative estimate as neither acute pain nor children are included.
Recent NCHS data suggest substantial rates of pain from various common causes. The percentage of Americans 18 and older who, in 2009, reported pain during the 3 months prior to the survey is shown in Table 2-1. Low back pain was the most frequently reported pain condition. A review of multiple epidemiologic studies of pain prevalence in various populations reveals two clear and consistent messages:
- Musculoskeletal pain, especially joint and back pain, is the most common single type of chronic pain.
- Most people with chronic pain have multiple sites of pain (Croft et al., 2010).
Rising Rates of Chronic Pain
An increase in pain prevalence has been recorded for some types of pain in the U.S. population,4 and chronic pain rates are likely to continue to rise, for at least five reasons.
First, the aging of the U.S. population means that a growing number of Americans will experience the diseases with which chronic pain is associated—diabetes, cardiovascular disorders, arthritis, and cancer, among others (Cherry et al., 2010).
4 Rising rates of chronic pain are not unique to the United States. A U.K. report, for example, notes that the prevalence of chronic pain is rising sharply: “chronic pain is two to three times more common now than it was 40 years ago” (U.K. Department of Health, 2009, p. 34).
Second is the rising prevalence of obesity, which is associated with chronic conditions that have painful symptoms (diabetes-associated neuropathy, for example), as well as orthopedic problems, including cartilage degradation (Richettel et al., 2011). As a result, more Americans will have joint replacement surgeries and at younger ages (Harms et al., 2007; Changulani et al., 2008); these surgeries, in themselves, can cause acute and sometimes persistent pain that interferes with a full recovery and a resumed quality of life. While it may be readily understood that increased weight places a greater burden on a person’s bones and joints—back, knees, hips—obesity also is associated with higher rates of other types of pain, notably migraine (Peterlin et al., 2009).
Third, progress in saving the lives of people with catastrophic injuries related to work, sports, vehicle crashes, or military combat who in previous times would have died creates a group of relatively young people at high risk of lifelong chronic pain. Similarly, modern medicine can help many people with serious illnesses survive longer, but the cost of survival may be debilitating pain. As one example, cancer chemotherapy can cause neuropathic pain.
Fourth, all surgical patients are at risk of both acute and chronic pain as a result of their procedure. Today, about 60 percent of surgical procedures in U.S. community hospitals are performed on an outpatient basis, and persistent problems with adequate pain control after ambulatory surgery are well documented. People may be discharged before their level of pain can be adequately assessed, or they may be unable to implement the prescribed pain management strategy at home. The greatest risk is that undermanaged acute postsurgical pain may evolve into chronic pain (Rawal, 2007; Schug and Chong, 2009).
Fifth, greater public understanding of chronic pain syndromes and the development of new treatments may cause many people who have not sought help or who previously gave up on treatment to reenter the health care system. Likewise, those who gain health care coverage under the recent health care reform legislation may newly seek care. In the past, many of these people were invisible to the system, so while their emergence does not affect the true number of people with chronic pain, it increases the size of the population under management.
A study of chronic low back pain conducted in North Carolina found “an alarming increase in the prevalence of chronic [low back pain] from 1992 to 2006 … across all population subgroups.” The prevalence for the total population studied more than doubled over the period, from about 4 to more than 10 percent, and for women (all ages) and men aged 45-54, prevalence nearly tripled (Freburger et al., 2009). Although these data are from a single state, a similar growth pattern has been seen in national data for users of the Department of Veterans Affairs health system, which show an annualized increase in prevalence of low back pain of about 5 percent per year, larger than increases in three other conditions studied (depression, diabetes, and hypertension) (Sinnott and Wagner, 2009). Further evidence of rising pain prevalence in the United States, based on NHANES data, is shown in Table 2-2. (The NHANES collected these data only through 2004.)
TABLE 2-2 Trends in Pain Prevalence, United States, 1999-2004
|People Who Reported Pain in||NHANES 1999-2000||NHANES 2001-2002||NHANES 2003-2004|
|Age 20 and over||22.2||25.7||27.7|
|Ages 20 to 44||15.7||19.5||19.6|
|Ages 45 to 64||28.5||31.7||35.6|
|Age 65 and over||33.1||34.2||36.3|
|White (not Hispanic)||24.4||28.6||30.6|
|Black (not Hispanic)||17.5||21.5||19.1|
|Below 100% of poverty level||26.3||28.6||29.0|
|100% to <200% of poverty level||25.4||30.7||29.0|
|≥200% of poverty level||20.0||23.6||27.9|
SOURCE: Unpublished data from the National Health and Nutrition Examination Survey, 1999-2004.
In nearly every demographic group, there has been a steady increase in reporting of pain prevalence across these surveys.
The potential impact of the growing prevalence of pain on the health care system is substantial. Although not all people with chronic low back pain are treated within the health care system, many are, and “back problems” are one of the nation’s 15 most expensive medical conditions. In 1987, some 3,400 Americans with back problems were treated for every 100,000 people; by 2000, that number had grown to 5,092 per 100,000. At the same time, health care spending for these treatments had grown from $7.9 billion to $17.5 billion. Thorpe and colleagues (2004) estimate that low back pain alone contributed almost 3 percent to the total national increase in health care spending from 1987 to 2000. While about a quarter of the $9.5 billion increase could be attributable to increased population size, and close to a quarter was attributable to increased costs of treatment, more than half of the total (53 percent) was attributable to a rise in the prevalence of back problems.
An important message from epidemiologic studies cited by Blyth and colleagues (2010) is “the universal presence across populations of characteristic subgroups of people with an underlying propensity or increased risk for chronic pain, in the context of a wide range of different precipitating or underlying diseases and injuries” (p. 282). These vulnerable subgroups are most often those
of concern to public health.5 Increased vulnerability to pain is associated with the following:
- having English as a second language,
- race and ethnicity,
- income and education,
- sex and gender,
- age group,
- geographic location,
- military veterans,
- cognitive impairments,
- surgical patients,
- cancer patients, and
- the end of life.
Many of these same groups also are at risk of inadequate treatment. Unfortunately, there have been no systematic national studies of rates of undertreatment among population groups, and the picture of undertreatment must be assembled from disparate pieces and small-scale studies. These assemblages do not provide a comprehensive view, but are consistent across population groups and settings. In fact, “most studies that have evaluated the potential for disparities in pain treatment on the basis of racial or ethnic differences have found them” (Portenoy et al., 2004, p. 326). Clearly, however, there is a need for more assessment of individual and group-related factors involved in seeking treatment for pain. Factors that discourage people from seeking treatment might include not only the typical and well-documented access barriers, such as lack of a usual source of care, but also “low levels of trust in clinicians, poorer expectations of treatment outcomes, language barriers and communication difficulties” (Dobscha et al., 2009, p. 1078). Under health care reform, increased access to health insurance may reduce rates of undertreatment, but the number of clinical, provider, and patient factors involved complicates the situation.
English as a Second Language
Census 2000 indicated that nearly three-quarters of Asian Americans spoke a language other than English at home, and almost 4 million Asian Americans were “low-English proficient” (Ro et al., 2009). Language problems are faced by many other groups as well. The largest group with such problems is the Hispanic population, with 28.1 million who speak Spanish at home and 13.8 million who speak English “less than very well” (Shin and Bruno, 2003). Non-English
5 The nomenclature used for different national, ethnic, and racial groups in this section of the report is that of the original sources.
speakers confront significant problems, especially relatively recent immigrants who are isolated by both language and culture when they encounter the complex U.S. health care system. They often are expected to follow complex home care and medication instructions, but the reasoning behind these directives may be both unclear and unfamiliar to them (Fadiman, 1997). Even for people whose first language is English, rates of health literacy are low (see Box 2-3).
Race and Ethnicity
Data weaknesses previously discussed are particularly important when one is examining racial and ethnic disparities, and only limited data are available on the prevalence of pain in certain population subgroups. Nonetheless, research
Beyond shortcomings in conventional literacy and English-language ability is the problem of limited health literacy, which is widespread and not confined to any one group or level of educational attainment, but compounded for individuals who have difficulties with English. At an Institute of Medicine workshop on medication use and health literacy, a participant underscored the problem of limited English proficiency in the populations served by many safety net providers (IOM, 2010).
To be “health literate” means that people can understand instructions on prescription drug bottles, health education brochures, and doctors’ directions and that they can negotiate complex health care systems. “Health literacy is not simply the ability to read. It requires a complex group of reading, listening, analytical, and decision-making skills, and the ability to apply these skills to health situations” (National Network of Libraries of Medicine, http://nnlm.gov/outreach/consumer/hlthlit.html). A person’s health literacy level is “the product of a complex set of skills and interactions on the part of the individual, the health-care system, the education system, and the cultural and societal context” (IOM, 2004, p. 59).
Problems with understanding medication instructions contribute to the estimated 1.5 million preventable adverse drug events that occur each year. Improved information about drugs merits special attention according to the National Action
Plan to Improve Health Literacy, released in 2010. “Individuals with limited health literacy skills are at particular risk for misunderstanding medical information” on product labels and package inserts (HHS and ODPHP, 2010. p. 19). Drugs for pain management are not exempt from these difficulties.
Specific to pain, a recent systematic review of evidence on health literacy interventions reported a study showing that people “with inadequate health literacy had higher probabilities of having activity limitations … and greater pain related to physical health than those with adequate health literacy” (HHS and
AHRQ, 2011a, p. 38).
suggests that cultural perspectives strongly influence reports of pain in general (Morris, 2003), as well as within specific racial/ethnic groups. Data also are needed with which to examine the quality of pain care provided to vulnerable subgroups, particularly longitudinal data that might document the rate of transition from acute to chronic pain. Still, the available data substantiate undertreatment of pain among racial and ethnic minorities for a wide range of settings and types of illness or injury (Anderson et al., 2009), although a few studies suggest that disparities in pain care may be decreasing (Quazi et al., 2008). These disparities also are seen for women versus men (as discussed in the section on sex and gender).
A robust finding across studies is that African Americans report greater pain than whites after surgery and in association with a variety of conditions, including AIDS, angina pectoris, arthritis, and headache, as well as some musculoskeletal conditions (Edwards et al., 2001). In the NHANES, blacks reported rates equal to those of whites for face/teeth pain and 1.5 times the rate of whites for abdominal pain; they were less likely than whites to report chronic pain in the back, legs/ feet, arms/hands, and chest (Hardt et al., 2008). Some researchers believe the clinical differences found in many studies are attributable at least in part to greater pain sensitivity and lower pain tolerance among African Americans. However, differences in definitions of pain, disease severity, assessment, population characteristics (e.g., age), and physician management may confound these findings, inasmuch as pain response is influenced by complex interactions of numerous factors—biological, emotional, and cultural.
In general, the pain literature has not explored the experiences of diverse populations, much less subpopulations of racial and ethnic groups, with respect to acute, chronic, or cancer pain. Relatively few experimental studies have been conducted to test possible racial and ethnic differences in pain sensitivity under controlled conditions, or to enable valid conclusions about the relevance of pain experiences under experimental conditions and the pain experiences of patients treated in pain centers (under relatively controlled circumstance) or in everyday clinical practice. Pain may be experienced very differently when associated with illness or disability than under time-limited laboratory conditions.
One experimental study in 337 subjects did find that African Americans reported higher levels of clinical pain and less pain tolerance than white subjects (Edwards et al., 2001). In that study, the differences found could not be attributed to such other factors as demographic profile; the duration, location, or number of sites of pain; previous surgeries; medication use; or psychological factors, such as depression, anxiety, or overall affective states. Prior studies had ruled out other possible explanations, including “personality, anxiety, education, family history of pain, attentional variables and peripheral mechanisms of
nociception” (Edwards et al., 2001, p. 320). Although underlying differences in pain response between blacks and whites were not explained by this study, the researchers hypothesized that they might be attributable to such factors as coping strategies, which vary among different cultures; social learning; attitudes; and a long-standing pattern of lower trust in medical research based on a grim history of exploitative research (Washington, 2006). In addition, minorities (as well as women) are at risk for poor physician–patient communication.
As more is learned about the role of various physiological factors in the body’s reaction to pain, including comorbidities and the genetic factors described in Chapter 1, these factors also may be found to affect differences between blacks and whites in pain perception and tolerance. However, too few genetic studies, like experimental pain studies generally, involve sufficient numbers of minority subjects, much less subgroups, to generate conclusions that might enable better targeted treatments.
Affecting the prevalence of pain in a population is the extent to which it is assessed and treated. Lower rates of clinician assessment of pain and higher rates of undertreatment have been found for African Americans in all settings and across all types of pain (Green et al., 2003a).
Undertreatment of pain among African Americans has been well documented. For example, children with sickle-cell anemia (a painful disease that occurs most often among African Americans) who presented to hospital emergency departments (EDs) with pain were far less likely to have their pain assessed than were children with long-bone fractures (Zempsky et al., 2011).
In general, moreover, a number of studies have shown that physicians tend to prescribe less analgesic medication for African Americans than for whites (Bernabei et al., 1998; Edwards et al., 2001; Green and Hart-Johnson, 2010). A study that used a pain management index to evaluate pain control found that blacks were less likely than whites to obtain prescriptions for adequate pain relief, based on reported pain severity and the strength of analgesics provided. Because such an index is a way to quantify a person’s response to pain medication alone, it is likely that people in this study did not receive other types of treatment for pain either.
Surgery is a frequent treatment for chronic joint pain. Data from the Health and Retirement Study were used to assess the need for joint replacement surgery (hip or knee) in almost 15,000 adults aged 60 and older; 2 years later, the same individuals were reassessed to determine whether the surgery was actually performed. African Americans who needed the surgery during the first assessment were less than half as likely to have undergone it than were whites; those without a college education were about two-thirds as likely to have received it. Such differences in surgery rates, which were not explained by differences in access to medical care or the amount of disability, perpetuate disproportionately high pain levels and disability among vulnerable groups (Steel et al., 2008).
Similarly, African Americans (and people of lower socioeconomic status) were found to be less likely to receive treatment or compensation in a St. Louis-
area study of outcomes of 1,475 workers’ compensation claims for low back injuries. Less treatment and compensation were associated with lower satisfaction with the workers’ compensation process, and lower satisfaction led to increased postsettlement disability among these workers. “Given that the function of Workers’ Compensation is to reduce disability from work-related injuries, the current results suggest that the system produces inequitable outcomes for these groups,” the authors conclude (Chibnall and Tate, 2005, p. 39).
A number of striking examples of African Americans’ lower likelihood of pain assessment and management were collected for the Institute of Medicine’s (2003) report Unequal Treatment: Confronting Racial and Ethnic Disparities in Health Care. These examples illustrate the pervasiveness of undertreatment of African Americans across settings, even in circumstances that appear “counterintuitive” (Barr, 2008).
One such study of patients with long-bone fractures in an urban Atlanta, Georgia, ED found that blacks were 1.7 times more likely than whites to receive no pain medication (Todd et al., 2000). Some years earlier, the same investigators had performed a comparison of ED treatment of long-bone fractures in whites and Hispanics in Los Angeles and found that Hispanics (discussed in the next section) were twice as likely as whites (non-Hispanics) to receive no ED pain medication (Todd et al., 1993). In the Atlanta study, medical records revealed that blacks and whites expressed their painful symptoms at similar rates (54 percent and 59 percent, respectively), which showed that the lower rate of receiving medication was not due to group differences in revealing pain or desire for relief, but “because the doctor didn’t order the medication” (Barr, 2008, p. 188). Such reports of ED undertreatment of blacks persist (Minick et al., in press).
Another counterintuitive example, in a different setting—nursing homes—found that among residents with cancer who were in daily pain, African Americans had a 63 percent greater likelihood of receiving no pain medication than whites (non-Hispanic) (Bernabei et al., 1998).
Racial and ethnic stereotyping by clinicians has been shown to affect prescribing patterns (Burgess et al., 2006). In one study, physicians presented with clinical vignettes of patients that differed by race (black or white), verbal behavior (“challenging” or “nonchallenging”), and nonverbal behavior (confident versus dejected versus angry) indicated they would be significantly more likely to increase the strength of opioid prescriptions for black patients exhibiting “challenging” verbal behavior (for example, asking for a medication by name, exhibiting anger); by contrast, they would be somewhat more likely to increase dosages for white patients exhibiting “nonchallenging” behavior (Burgess et al., 2008). These results indicate the complexity of the relationship among patient race and behavior and physicians’ decisions about treatments.
Unequal Treatment cites three types of provider factors that might help account for such disparities in care: “bias (or prejudice) against minorities; greater clinical uncertainty when interacting with racial and ethnic minority patients;
and beliefs (or stereotypes) held by the provider about the behavior or health of minorities” (IOM, 2003, p. 9). (It should be noted that a number of the patterns of undertreatment cited above also occur among women and the elderly, both discussed below.) When people perceive discrimination in their lives, that perception in and of itself is associated with greater pain according to a survey of older African American men (Burgess et al., 2009).
Hispanics are at high risk for pain and pain undertreatment, given their lower education and income levels and higher rates of overweight, lack of health insurance, lack of a usual source of care, limited English proficiency, and poor communication with health care providers.
Similar to differences within the Asian American population discussed below, there are important variations in rates of pain-related conditions among Hispanic subgroups. A secondary analysis of pain prevalence using age-adjusted NHANES data to estimate the prevalence of current, nonminor pain showed that Mexican Americans, who constitute the largest Hispanic group in the United States, are less likely to report chronic limb pain, back pain, or face/teeth pain than either blacks (non-Hispanic) or whites (non-Hispanic) (Hardt et al., 2008). The only category of chronic pain that Mexican Americans reported at a rate equal to that of whites was abdominal pain. Puerto Ricans and those born in the United States and having higher degrees of acculturation, including greater English proficiency, have the highest rates of chronic back and neck problems (Bui et al., 2011).
The secondary analysis of NHANES data cited above also found that Mexican Americans reported widespread pain only about half as often as blacks (non-Hispanic) or whites. The confidence intervals around the prevalence estimates for the three population groups are fairly wide, but based just on the percentages, the data suggest that only about 2 percent of Mexican Americans (men and women) report widespread pain, compared with black men (more than 3 percent), black women (4 percent), white men (just under 3 percent), and white women (5 percent).
Some comparisons of Hispanics and whites with comparable serious health problems have found that Hispanics report more pain. Depression is associated with more pain reports in both groups, although it does not erase the differences in pain reports for Hispanics. These differences have been attributed to “cultural differences in the acceptability and the expression of distress” (Hernandez and Sachs-Ericsson, 2006). Findings such as these, as well as the association between acculturation and back and neck pain noted above, underscore the importance of the comprehensive approach to assessing pain explored in Chapter 1. Such an approach emphasizes not only understanding biological conditions that give rise to pain (e.g., injury, disease), but also psychological factors (e.g., coping strategies,
beliefs) and social factors (e.g., cultural norms) that may shape the way pain is experienced and expressed to others.
Finally, Hispanics, like African Americans, experience disparities in pain care. A study focusing on differences in emergency care for Hispanics, for example, found that for all injuries combined (long-bone, back, migraine), Hispanics (as well as blacks) were significantly less likely to be provided with an opioid drug (Tamayo-Sarver et al., 2003). The authors of this study hypothesize that “differences in patient assertiveness, physician perception of the patient, and social distance may contribute to differences in physician-patient communication and trust that are responsible in part for the racial/ethnic disparities in analgesic prescription” (p. 2071). Likewise, Bernabei and colleagues (1998) found that Hispanic cancer patients, like African Americans and Asians (see below), experienced an excess risk (relative to whites) of receiving no analgesia.
NHIS data suggest that Asian Americans overall have lower self-reported pain prevalence than non-Hispanic whites (CDC and NCHS, 2010). However, Asian American communities in the United States represent many different national origins, cultures, languages, traditions, and ethnicities. Important variations exist among these subgroups. The few available data for Native Hawaiians and Pacific Islanders, for example, suggest high rates of low back pain. Likewise, data from the 2006 NHIS revealed that migraines and severe headaches were more likely to be reported by adults who were Vietnamese (13 percent) or Filipino (11 percent) than by those who were Chinese (7 percent) (Barnes et al., 2008). Moreover, there are more differences within than among these population groups.
In general, the differential in self-reported pain prevalence for Asian Americans is attributable to cultural factors such as stoicism and reluctance to report pain (a sign of weakness) or accuse health professionals of inadequate care (respect). Also, Asian Americans may request less pain medication or stop using it because of fears of side effects. Analyses of Chinese patients (the largest Asian subgroup in the United States), for example, suggest that barriers to cancer pain care may include low English proficiency, the belief that pain will be a burden to family members, and “deeply-rooted values and beliefs of stoicism and fatalism which inhibit pain expression” (Dhingra, 2008, p. 29).
At the same time, survey data from 2001 indicate that a lack of good doctor–patient communication may be part of the problem. Compared with whites, Asian Americans were less likely to believe their doctor understood their background and values (62 percent for whites versus 50 percent for Asian Americans), listened to everything they had to say (69 percent versus 47 percent), or involved them in decisions about their care as much as they wanted (80 percent versus 60 percent) (Ngo-Metzger et al., 2004). More recent data
suggest that such poor communication persists. Even among those who have had at least some college education, Asians are more likely than blacks or whites to have had poor communication with health professionals (AHRQ, 2011). The difficulties associated with having English as a second language discussed above are a factor in this problem.
American Indians and Alaska Natives
American Indians and Alaska Natives have repeatedly been found to have markedly higher rates of reported pain overall and for specific sites (e.g., severe headache or migraine, low back pain, neck pain, joint pain) (CDC and NCHS, 2010; Jimenez et al., 2011). They also have high rates of diseases and health conditions, such as diabetes, arthritis, and obesity, that often produce significant pain (Moulton et al., 2005). For example, the 2007 age-adjusted death rate for diabetes mellitus among American Indians and Alaska Natives was 37.2 per 100,000, compared with 22.5 for the population as a whole (CDC and NCHS, 2010). Some evidence that certain autoimmune rheumatic diseases are more prevalent in American Indians than in Alaska Natives or the non-Indian population suggests that at least some of the difference in prevalence rates may be genetic (Kramer et al., 2002).
In the Health and Retirement Study,6 which interviewed people aged 51-61, more than 15 percent reported that “pain made it difficult to do normal work.” American Indians reported the highest rates of difficulty (25 percent), although they were less likely than other groups to report their pain as severe (Kramer et al., 2002).
The Indian Health Service (IHS) serves the nation’s American Indian and Alaska Native population of 2.9 million spread across the continent in tribal and nontribal, urban and rural areas but has only one pain clinic, according to the Health Policy Research Director of the InterTribal Council of Arizona, Inc. (Wilner, 2008). Some 58 percent of American Indians and Alaska Natives live in urban areas, not on reservations, and may have less access to IHS programs, where they would be more likely to find culturally competent care. IHS’s Urban Indian Health Program (UIHP) comprises 34 nonprofit programs nationwide, with an additional 18 cities having American Indian populations large enough to support a UIHP.7
In traditional American Indian culture, healing involved the whole community, but modern medicine is more likely to involve a patient–clinician or, at best,
6 The University of Michigan’s Health and Retirement Study is a longitudinal study that surveys more than 22,000 Americans aged 50 and older every 2 years. Supported by the National Institute on Aging and the Social Security Administration, it studies labor force participation and health transitions near the end of people’s working lives and into retirement.
7 IHS programs are chronically underfunded—the agency estimates that its funding is only 22 percent of what is needed for primary care services (HHS and IHS, 2011).
a family–clinician relationship. Various cultural attributes may lead to underreporting of pain in particular tribes or groups, hindering clinicians in adequately assessing the severity of reported pain.
In-depth interviews with a small group (45) of urban American Indians with joint or musculoskeletal pain revealed that, although 70 percent had discussed their pain symptoms with a doctor, they often did not describe their level of pain or dysfunction directly but “in a subtle, guarded manner” (Kramer et al., 2002, p. 592). When asked what they would most like doctors to know about treating American Indians, the interviewees, who represented some 30 tribal affiliations, spoke openly about their cultural practice of minimizing pain complaints and noted that they generally “do not readily ask for help, discuss pain, or disclose the intensity of a painful episode.” This finding suggests a strong likelihood of underdiagnosis and undertreatment of pain in this population.
Income and Education
Higher pain rates among U.S. racial and ethnic minority groups can be traced in part to strong income and educational gradients in pain prevalence, with less pain being reported as a person’s educational and income levels rise. The far right columns in Tables 2-3 and 2-4 show the ratio between the lowest and highest prevalence for each pain condition. For example, a person with no high school diploma or general equivalency degree (GED) is 1.33 times more likely to suffer from severe headache or migraine than a person with some college or more. Again, low back pain is the most common condition reported, regardless of education.
TABLE 2-3 Age-Adjusted Rates of U.S. Adults* Reporting Pain in the Last 3 Months, Selected Causes, by Education, 2009
|People Who Reported Pain in||NHANES 1999-2000||NHANES 2001-2002||NHANES 2003-2004|
|Age 20 and over||22.2||25.7||27.7|
|Ages 20 to 44||15.7||19.5||19.6|
|Ages 45 to 64||28.5||31.7||35.6|
|Age 65 and over||33.1||34.2||36.3|
|White (not Hispanic)||24.4||28.6||30.6|
|Black (not Hispanic)||17.5||21.5||19.1|
|Below 100% of poverty level||26.3||28.6||29.0|
|100% to <200% of poverty level||25.4||30.7||29.0|
|≥200% of poverty level||20.0||23.6||27.9|
*Those aged 25 and older.
SOURCE: CDC and NCHS, 2010.
TABLE 2-4 Age-Adjusted Rates of U.S. Adults Reporting Pain in the Last 3 Months, Selected Causes, by Poverty Level, 2009
|Cause of Pain||No High School Diploma or GED (%)||High School Diploma (%)||Some College or More (%)||Ratio between Highest and Lowest Education Groups|
|Severe headache or migraine||19.9||16.2||14.9||1.33|
|Low back pain||35.0||32.2||27.4||1.28|
SOURCE: CDC and NCHS, 2010.
To the extent that pain interferes with completion of education or full employment, it may contribute to lower educational and income status. Or, referring back to the discussion of allostatic load in Chapter 1, the cumulative burdens of high-stress environments in childhood may contribute to both a higher likelihood of pain and lower achievement levels. A well-documented set of U.K. studies of the influence of occupational rank on health found that people in the lowest-ranking jobs (clerical and manual labor) had a death rate 3.5 times that of those in the administrative ranks, as well as similarly higher rates of serious diseases—heart disease, stroke, lung cancer, injuries, and suicide (Russo, 2011). The influence of social class held even when data were controlled for various risk factors, such as smoking. These results provide further evidence of the impact of allostatic load on health.
Education, employment, and poverty are commonly used measures of socioeconomic status and the broader construct of “social class.” These three factors work together to help explain health disparities by race and ethnicity. Socioeconomic status can be measured at the individual, family/household, and neighborhood levels. It influences a person’s health status in many ways, including the likelihood of having chronic pain, and “increasing neighborhood [socioeconomic status] improves the chronic pain experience for both blacks and whites” (Fuentes et al., 2007, p. 1160). Indeed, “population-based studies have consistently shown that chronic pain occurrence is inversely related to socioeconomic status” (Blyth, 2010, p. 22).
The associations among race, neighborhood socioeconomic status, medical care, and chronic pain are “important factors in initiating and maintaining racial disparities in health” (Williams and Jackson, 2005, p. 325). Accounting for both social class (education, employment, and poverty) and race may produce the most accurate perspective on health disparities (Kawachi et al., 2005). According to Kawachi and colleagues, “Even if racial disparities in health outcomes could be eliminated, most blacks [and some other minority groups] would still have worse health than the U.S. average because of their class position” (p. 346), which suggests that efforts to eliminate health disparities should not concentrate on racial and ethnic inequalities alone.
With regard to the income and education components of social class, a survey by Portenoy and colleagues (2004) found a higher prevalence of disabling pain among people with incomes of $25,000 or less (odds ratio 1.71 [p = .001]) and less than a high school education (odds ratio 1.72 [p = .001]) than among respondents with higher income and education levels. These disadvantages (along with being unemployed) remained significant even after controlling for other demographic factors. In this study, neither African American race nor Hispanic ethnicity predicted the likelihood of having disabling pain, although individuals from those groups were more likely to have the socioeconomic disadvantages that predicted pain.
Sex and Gender
Across nations, women consistently report a higher prevalence of chronic pain than men (Croft et al., 2010) and are at greater risk for many pain conditions (Fillingim et al., 2009). In the NHANES, in every ethnic/racial category, women reported widespread pain more often than men (Hardt et al., 2008).
Sex and gender differences in pain and pain perception are associated with numerous conditions. Women are likely to have more pain from certain diseases; for example, women with cancer report greater pain severity than men, as well as higher rates of depression. Both of these differences are statistically significant (Green et al., 2011). A number of chronic pain syndromes occur only in women, and others occur predominantly (80 to 90 percent) in women. These conditions include chronic fatigue syndrome (estimated at 1-4 million people affected nationally), endometriosis (6.3 million), fibromyalgia (6 million), interstitial cystitis (1 million), vulvodynia (6 million), and temporomandibular disorders. In total, perhaps 50 million women have one or more of these conditions, which frequently co-occur (Campaign to End Chronic Pain in Women, 2010; TMJA, 2010).
Common types of pain that affect both men and women vary markedly in prevalence by sex (Table 2-5). U.S. women’s rates of headache and some categories of joint pain are considerably higher than men’s.
These differences have been found in both clinical and experimental settings (Fillingim et al., 2009). In experimental studies, women have shown both lower
TABLE 2-5 Age-Adjusted Rates of U.S. Adults Reporting Pain in the Last 3 Months, Selected Causes, by Sex, 2009
|Cause of Pain||Males (%)||Females (%)||Ratio|
|Severe headache or migraine||10.1||21.9||2.17|
|Low back pain||26.0||30.1||1.16|
SOURCE: CDC and NCHS, 2010.
thresholds and less tolerance for pain, linked in part to hormone levels (Fillingim et al., 2009; IOM, 2011). Differences in chronic pain rates may occur because of “hormonal fluctuation, criterion effects, differences in body size, skin thickness, blood pressure, social expectations, cognitive variation, method of stimulation, and differences in psychological traits such as anxiety and depression” (Derbyshire, 2008, p. 1).
At least three theories have been proposed to explain the marked differences in pain experience by sex and gender:
- a gender-role theory that assumes it is socially more acceptable for women to report pain,
- an exposure theory that suggests women are exposed to more pain risk factors, and
- a vulnerability theory proposing that women are more vulnerable to developing musculoskeletal pain (Picavet, 2010).
Of these, the vulnerability theory is best supported by scientific evidence, including the potential role of sex hormones in nociception, as well as differences in psychological reactions and coping strategies.
Adverse drug effects and complications also are more common in women than men (Snidvongs and Holdcroft, 2008). Responses to analgesia may vary for many potential reasons: hormonal factors, physiology, psychological and sociocultural factors, and possibly genetic factors related to metabolism of therapeutic medications. Thus, “the possibility of sex and gender differences in the context of pain treatment—especially when analgesics are prescribed—cannot be dismissed” (Fillingim et al., 2009, p. 462). Greater understanding of the causes of the sex and gender differences in analgesia responses may reveal promising targets for improvements in therapeutic interventions (Paller et al., 2009).
Like the racial/ethnic groups discussed above, women experience disparities in pain care. In addition, some of the sex-linked conditions cited earlier are not well understood, and women with these conditions have faced not only severe pain, but also misdiagnoses, delays in correct diagnosis, improper and unproven treatments, gender bias, stigma, and “neglect, dismissal and discrimination” from the health care system (Campaign to End Chronic Pain in Women, 2010, p. 4).
Disparities in pain prevalence and care have been documented for both children and the elderly.
Children experience acute and chronic pain associated with routine childhood illnesses (ear infections, for example) and injuries (musculoskeletal injuries, abuse, burns), as well as with chronic diseases that emerge in childhood (sickle-cell anemia, cystic fibrosis) or usually are associated with older populations (cancer, HIV infection). Some diseases (diabetes, fibromyalgia) have “juvenile” forms. Neuropathic pain in children is increasingly recognized but still relatively rare (Walco et al., 2010). Most data on the prevalence of pain in pediatric populations focus on just one or two disease subpopulations, limiting information on pain prevalence among children in general (Goldstein and Sakae, 2010). As children move through adolescence, however, the prevalence of many types of pain approaches adult rates.
Children suffer from many of the common types of pain, such as headaches, that adults experience. NHANES data indicate that 17 percent of U.S. children aged 4-18 experience frequent or severe headaches, including migraine, over the course of a year. Before puberty, boys and girls have headaches at approximately the same rate, but after age 12, the rate of recurrent and severe headaches rises among girls. As in adults, other physical conditions—in this case, asthma, hay fever, and ear infections—occur more frequently in children and teens with recurrent headaches (42 percent) than in those without (25 percent) (Lateef et al., 2009).
Good pain management in children often is not achieved. The path to identifying an effective treatment begins with recognition of the problem—the diagnosis. However, researchers involved in most studies of headache in children, for example, comment on both the underdiagnosis of the condition, even when it is serious, and the significant impact headaches have on children’s lives (Lopez and Rothrock, 2010; Winner, 2004).
Once children’s pain is recognized, moreover, it often is undertreated for various reasons, and the consequences may include behavioral changes and adverse effects on child development (Howard, 2003). One factor contributing to undertreatment is that prescribing pain medications for children requires “creativity and
adaptability” (Gregoire and Finley, 2007, p. 95) given the lack of evidence-based recommendations for children and adolescents for many pain medications. Clinicians may be unsure how to convert adult doses to child doses that will be both safe and efficacious,8 and in line with the recognition that “children are not just small adults,” they may hesitate to prescribe certain psychoactive medications for children, whose bodies and brains are still developing. Well-publicized instances of antidepressants and other medications being linked to teen suicide have led to further caution.
Research has documented numerous examples of situations in which children may not receive appropriate pain care:
- In the regular ED—In one academic medical center studied, very few children undergoing a laceration repair received antianxiety medication or procedural sedation, which often are indicated (Brodzinski et al., 2010).
- In the pediatric ED—A study of pediatric ED care provided to 180 children with long-bone fractures or second- or third-degree burns found that almost two-thirds (65 percent) of those under 2 years of age and almost half (48 percent) of those aged 6-10 received no analgesia (Alexander and Manno, 2003).
- When the condition is unexpected—Girls with endometriosis, a condition that is usually diagnosed in women aged 25-30, often are undiagnosed and undertreated.
Moreover, the same disparities in care experienced by adults also may affect racial and ethnic minority children with pain (Linton and Feudtner, 2008). For example, one study found that Latino children undergoing an adenoidectomy or tonsillectomy received less opioid medication than their white, non-Hispanic counterparts (Jimenez et al., 2010). If a child is part of a discernible ethnic, religious, or racial group, the clinician may either stereotype the group’s attitude toward pain or encounter cultural aspects of pain, such as stoicism; either way, the clinician may fail to focus on the individual child’s needs (Finley et al., 2009).
Data on the prevalence of chronic pain among older adults living outside institutions range from 18 to 57 percent. Much of the variation derives from
8 The Best Pharmaceuticals for Children Act of 2007 extends patent protection for pediatric medications as an incentive for the pharmaceutical industry to research and manufacture drugs for children, and expands National Institutes of Health research on children (Politis, 2005; Best Pharmaceuticals for Children Act Reauthorization of 2007, Public Law 110-85, Title V, part of the Food and Drug Administration Amendments Act [September 27]).
different definitions of chronic pain. Most researchers who use a definition of chronic pain similar to “persistent or recurrent pain for at least 3-6 months” have found chronic pain in about half of individuals surveyed (Thomas, 2010, p. 186). Across studies, the association of pain with age is not uniform; some studies do not find an association, and some attribute it to greater reporting of symptoms. However, more severe pain and pain that interferes with activities do appear to increase in frequency with age.
Experimental studies show that older populations have “a modest and somewhat inconsistent age-related decline in pain sensitivity to mild noxious stimuli,” which might lead to underreporting of milder pain symptoms (Gibson, 2006, p. 2). However, both experimental and clinical studies have shown that elderly people are more vulnerable to severe or persistent pain and that the inability to tolerate severe pain increases with age.
Some of the specific causes of pain in older people include
- joint pain (mostly osteoarthritis), which has a significant negative impact on health-related quality of life;
- postsurgical pain, with people aged 65 and older being 2.6 times more likely to have surgery than those aged 45-64 (Hall et al., 2010);
- chronic disease, as the prevalence of chronic diseases that can cause pain rises with age; and
- conditions associated with aging, such as shingles (which about one of three U.S. residents will acquire at some point in life), about half of which occur among people 60 and older (CDC, 2011).
Also at risk of severe pain are elderly people with musculoskeletal disorders, such as degenerative spine conditions and arthritis, or with nighttime leg pain, pain from claudication (leg weakness), or cancer.
Factors affecting the severity of pain in the elderly include
- complex manifestations of pain;
- underreporting of pain;
- concurrent problems and multiple diseases (comorbidities), which complicate diagnosis and treatment;
- higher rates of medication side effects; and
- higher rates of treatment complications (American Geriatrics Society, 2009).
In general, these same factors also contribute to the documented undertreatment of pain in the elderly, along with the lack of an evidence base concerning the pharmacokinetic and pharmacodynamic changes that occur with aging (Barber and Gibson, 2009). Similar to the situation with children in the past, elderly people rarely are included in clinical trials of medications, so clinicians have
inadequate information about appropriate dosages and potential interactions with medications being taken for other chronic diseases (Barber and Gibson, 2009).
A study of more than 13,000 people with cancer aged 65 and older discharged from the hospital to nursing homes found that, among the 4,000 who were in daily pain, those aged 85 and older were more than 1.5 times as likely to receive no analgesia than those aged 65-74; only 13 percent of those aged 85 and older received opioid medications, compared with 38 percent of those aged 65-74 (Bernabei et al., 1998). (A similar excess risk of receiving no analgesia was found among African Americans, Hispanics, and Asians compared with whites.)
Comprehensive, academically based pain treatment centers are relatively few in the United States and, understandably, not available to most residents living outside major cities. At the same time, many aspects of rural life—especially farming and ranching—are hazardous (Table 2-6). The federal Bureau of Labor Statistics combines agriculture, forestry, fishing, and hunting in a single occupational category that has by far the highest rate of fatal occupational injuries of any other category—more than twice the rate of the mining and transportation industries, for example. This finding suggests a high rate of serious injuries as well, which carry the risk of concomitant pain (DOL and BLS, 2010).
There are more than 23 million U.S. military veterans, about a quarter of whom receive health care services through the Department of Veterans Affairs.
TABLE 2-6 Age-Adjusted Rates of U.S. Adults Reporting Pain in the Last 3 Months, Selected Causes, by Place of Residence, 2009
|Cause of Pain||Residence within Metropolitan Statistical Area (MSA) (%)||Residence outside MSA (%)||Ratio Non-MSA/MSA|
|Severe headache or migraine||15.5||19.3||1.25|
|Low back pain||27.1||33.3||1.23|
SOURCE: CDC and NCHS, 2010.
The Iraq and Afghanistan conflicts have challenged the Department of Defense and the Department of Veterans Affairs with a large, new cohort of injured service members and veterans. “Painful musculoskeletal conditions are by far the most common diagnosed medical problems among these veterans, far surpassing the prevalence of other medical and mental health disorders” (Kerns and Dobscha, 2009, p. 1161).
Further, the prevalence of musculoskeletal pain has been found to increase each year following deployment, especially for women (Haskell et al., in press). Pain was assessed in a group of more than 91,000 veterans receiving care from the Department of Veterans Affairs who were discharged from the military between October 1, 2001, and November 30, 2007. Some 43 percent reported “any” pain, and among those reporting pain, 63 percent (more than 25,000 men and women) reported moderate to severe pain (Haskell et al., 2009).
Tremendous advances in military medicine have allowed large numbers of seriously injured service members to survive despite wounds that in past wars would have been fatal (President’s Commission on Care for America’s Returning Wounded Warriors, 2007). State-of-the-art burn care and postamputation care have saved lives and restored functioning for many catastrophically injured service members, as has improved care for traumatic brain injuries.
The urban character of the Iraq war, combined with long and multiple deployments, has exposed service members not just to more injuries but also to new and extraordinary stressors (Gironda et al., 2006). One result is unprecedented rates of posttraumatic stress disorder (PTSD).
Many wartime injuries are associated with severe pain. Burns are extremely painful, and the treatment for severe burns may take a decade of successive surgeries and rehabilitation; amputees may suffer from “phantom limb pain”; and PTSD, traumatic brain injury, and chronic pain co-occur, complicating treatment of all three conditions. In a study population recruited from a Department of Veterans Affairs’ Polytrauma Network site, 42 percent of veterans had concurrent chronic pain, PTSD, and persistent postconcussive symptoms (Lew et al., 2009). In fact, the authors said, each of these conditions “rarely occurs by itself” (p. 701). The most common pain locations were the back (58 percent) and head (55 percent).
The demographics of deployed service members also have changed. The military services now include many more women, as well as Reserve and National Guard units that generally comprise older men (Gironda et al., 2006). As discussed earlier, increased age and female sex are both linked to higher pain rates in the population at large. In the first year after their last deployment, a comparison of male and female veterans found that the females were less likely to report pain, but those who did so were more likely to report moderate to severe pain and less likely to report persistent pain (Haskell et al., 2009). By 7 years after deployment, women were significantly more likely than men to report back, musculoskeletal, and joint problems (Haskell et al., in press).
The Department of Veterans Affairs also serves veterans of the Persian Gulf and Vietnam wars, many of whom are in their 60s and early 70s, as well as even older veterans from the Korean conflict and World War II. The latter groups are prey to all the pain-related problems of the elderly in addition to any lasting disabilities associated with their military service.
People with Cognitive Impairments
People with cognitive impairments, including dementia, may be unable to convey information to clinicians about their pain. The usual assessment of pain relies heavily on self-report—“the gold standard for measuring pain in research and clinical care”—and for the most severely affected, other means must be used to assess pain (Ersek et al., 2011). Reports from proxies (family members, friends, caregivers), health history (if known), and observation may have to substitute for first-person evidence
Nearly 1.5 million Americans live in the nation’s nursing homes according to the 2004 National Nursing Home Survey (NNHS) (Jones et al., 2009). The most common primary diagnosis for these residents is diseases of the circulatory system (25 percent), followed by mental disorders (22 percent) and diseases of the nervous system (16 percent), which include Alzheimer’s disease (11 percent). Combining the percentages for mental disorders and Alzheimer’s disease suggests that a third of nursing home residents have a serious condition that might interfere with self-reports of pain. This is likely an underestimate inasmuch as some level of mental disorder might be found among residents with many other conditions considered “primary”—for example, the approximately 5 percent of those the survey identified as having acute but ill-defined cerebrovascular disease.
A frequently cited study of the prevalence of pain in nursing home residents found that, despite the prevalence of cognitive deficits, 62 percent had complaints of pain (primarily musculoskeletal), while 21 percent were “unable to make their needs known” (Ferrell et al., 1995). A trained study team nurse conducted all the resident interviews and attempted to determine pain status, taking care “to give subjects ample time to complete each task” (p. 594). The authors suggest that cognitive impairments are “a substantial barrier to pain assessment and management,” (p. 591), but working with a variety of scales, assessment could be accomplished in residents with mild to moderate impairments.
Data from the NNHS suggest that about a quarter of nursing home residents report or show signs of pain (Sengupta et al., 2004). Some of the differences in recorded pain rates across studies are likely attributable to how the data were gathered. In contrast to the study by Ferrell and colleagues described above, the NNHS interviewers did not talk to patients directly, but interviewed designated staff reportedly familiar with the residents and their care.
How persistent (versus prevalent) is pain in nursing homes? A study of all 2.2 million residents of U.S. nursing homes in 1999 used the Centers for Medi-
care and Medicaid Services’ (CMS) Minimum Data Set in an attempt to answer this question. Residents with “persistent pain” were defined as those who were in pain at an initial measurement point who were still having “daily moderate or excruciating pain” at a second assessment 60 to 180 days later (Teno et al., 2001). The results indicated that nationally, nearly 15 percent of residents still in a nursing home at the time of the second assessment were in persistent pain, and more than 41 percent of those who had been in pain at the first assessment were in severe pain 60 to 180 days later. In most states (41), 39-46 percent of nursing home residents were in persistent pain. This figure is substantially higher than the NNHS or CMS estimates. Even so, Teno and colleagues (2001) believe it is an underestimate because the data were reported by staff, not by residents themselves.
Three factors combine to make the adequate treatment of pain among the large proportion of nursing home residents with dementia and other cognitive deficits a significant concern. First are demographic shifts that are producing a growing number of elderly: in 2000, more than 12 percent of Americans were 65 and older, a rate expected to reach nearly 20 percent by 2030 (Chapman et al., 2006). The growth is especially important among the “oldest old,” who are most responsible for the rising prevalence of dementia (Brookmeyer et al., 2011). Second is the increase in pain levels among the elderly from multiple causes, described above, which should affect people similarly regardless of whether they have dementia (Weiner et al., 1999); that is, there is no reason to think that people with dementia are exempt from these other sources of pain. And third is the finding from research showing the lower likelihood that people with cognitive impairments, especially dementia, will ask for and receive pain medication (Buffum et al., 2007).
Nursing home residents with versus those without dementia are less likely to report or show signs of pain (Sengupta et al., 2010), with rates of reported pain prevalence declining as the severity of cognitive impairment increases (Reynolds et al., 2008). Among residents at the most severe level, only 10 percent are reported to be “in pain.” The Sengupta et al. and Reynolds et al. studies differ in their conclusions as to whether dementia affects treatment; however, undertreatment of pain in this population could lead to further health and mental health problems among residents, increased demands on facility staff and families, and higher costs of care. There is every reason to believe that pain in nursing home residents with dementia is a serious problem requiring attentive management.
Ironically, chronic pain often results from interactions with the health care system. Ten to 50 percent of people undergoing common surgical operations (groin hernia repair, breast and thoracic surgery, leg amputation, and coronary artery bypass surgery) develop persistent pain, and for 2-10 percent of them, the
pain is severe (Kehlet et al., 2006). Inadequately treated pain after heart surgery, for example, inhibits healing and increases the risk of myocardial ischemia, stroke, and bleeding, among other complications, through such mechanisms as increased heart rate, systematic vascular resistance, and circulating stress-related hormones (catecholamines). Every effort should be made to avoid nerve damage in surgery, and actions to control pain after surgery should be initiated early, especially if pain is acute, because acute postsurgical pain increases the risk of developing a chronic pain syndrome (Kehlet et al., 2006).
Although the incidence of some common cancers has declined population-wide, longer survival times and the growing number of Americans who are elderly, in whom cancer incidence is highest, may overwhelm these recent declines. The prevalence of cancer in 2010 was estimated at 13.8 million Americans and projected to be 18 million in 2020, with the growth due primarily to the increased size of the over-65 population (Mariotto et al., 2011).
Most people with advanced cancer (60-85 percent) report pain (Green et al., 2011), with prevalence depending on the type of cancer and its stage. In a recent survey of people with cancer, 44 percent overall had experienced pain with the disease. This was the case for breast cancer (58 percent), colorectal cancer (41 percent), lung cancer (56 percent), multiple myeloma (100 percent), and prostate cancer (28 percent). Most of the people in this survey were cancer free or in remission; nevertheless, about one in five had current pain. In 44 percent of respondents, pain was “flares only,” meaning that they experienced sharp increases in pain over their usual background level, usually of short duration. Frequently, flares were associated with activity (42 percent).
A meta-analysis of 52 studies of pain among people with cancer likewise indicated the high prevalence of pain in this population. Some 64 percent of people with metastatic or advanced-stage disease had pain, as did 59 percent of those undergoing anticancer treatment and 33 percent who had completed curative treatment (van den Beuken-van Everdingen et al., 2007). Other studies have shown generally comparable results (Green et al., 2011). Because increasing numbers of people with cancer survive, the United States will have a significant and growing number of people with residual pain even after successful cancer treatment.
With respect to pain care, analysis of 26 international studies showed that across nations, nearly half of cancer patients’ pain was undertreated. Higher-income countries such as the United States performed better than other countries, a finding attributed to better clinician education, stronger pain treatment programs, and insurance coverage of medications. However, the eight U.S.-specific studies analyzed found a wide range of reported undertreatment, from 8 to 65 percent, with a weighted mean of 39 percent (Deandrea et al., 2008).
People at the End of Life
Preventing and relieving pain and other symptoms experienced when a person is approaching death is an essential obligation of health care professionals. Yet “too many dying people suffer from pain and other distress that clinicians could prevent or relieve with existing knowledge and therapies” (IOM, 1997, p. 2). Approximately two-thirds of people with advanced cancer experience pain, and almost three-quarters of those admitted to hospitals report pain at the time of admission. Studies of people in palliative care units reveal that “pain often is the dominant symptom” (Paice, 2010, p. 161).
Hospice and palliative care programs place great emphasis on pain management and achieve significantly improved patient outcomes (Higginson and Evans, 2010). Frequently they must rely on opiate medications at levels that would be inappropriate in other, nonterminal situations. Even in these settings, however, pain is still common. A third of people enrolled in hospice reported pain at the last hospice care visit before death (CDC and NCHS, 2010). Given the relatively short lengths of enrollment in hospice for many people, this statistic suggests that many people do not receive the full potential benefit of this service. One study of 106,500 hospice decedents found that, regardless of length of stay, a consistent 5-7 percent of patients wanted more help with pain management (Teno et al., 2007).
Teno and colleagues (2007) suggest that, rather than length of stay per se, it is “the perception of being referred ‘too late’” (p. 123) that is associated with greater unmet needs, more family concerns, and lower satisfaction with care. About twice as many bereaved family members who believed the hospice enrollee had been referred “too late” reported that the decedent did not receive an appropriate amount of help with pain compared with those who thought referral came “at the right time” (10 percent versus 5 percent).
The pain level from this thing is in the 10 category, and I don’t say 10 lightly. There is no way to function. It involves clawing at the air and screaming into a pillow for 24 hours at a crack. … Years and years.
—A person with chronic pain9
Understandably, pain prevalence estimates decrease as the severity of pain and its effects increases. Studies across countries suggest that approximately
9 Quotation from response to committee survey.
25 percent of people suffer moderate or severe pain. In the United States, about 10 percent have severe disabling chronic pain (Croft et al., 2010). No simple clinical test can assess a person’s subjective experience of pain. Seriousness depends on self-report and to some extent can be inferred from pain’s impact on a person’s activities of daily living, ability to work, and quality of life. The seriousness of pain also is manifest in the observed link between chronic pain and the risk for suicide. This section reviews the evidence on these manifestations of the seriousness of pain, as well as differences by race/ethnicity and sex in the risk for disabling pain.
Effects on Activities of Daily Living
The NHIS asks Americans who have had pain in the last 3 months whether they had any difficulty with basic activities or experienced limitations in complex activities as a result of their pain (Table 2-7). The most common reported cause of disability was any type of joint pain, followed by low back pain. Disabling knee pain was reported by almost 40 percent, and headache and neck pain each reportedly caused disability in about a third of respondents.
Effects on Productivity
Pain has long been recognized as having a widespread adverse effect on America’s workforce. More than half of 29,000 respondents to the American Productivity Audit telephone survey reported experiencing headache or musculoskeletal pain-related conditions during the previous 2 weeks (Stewart et al., 2003). One in 8 respondents said their pain caused a loss of productive time, and
TABLE 2-7 Extent of Pain-Related Disability among Adults with Pain in the Last 3 Months, United States, 2009
|Type of Pain||Difficulty with Basic Actionsa (%)||Complex Activity Limitationb (%)|
|Severe headache or migraine||31.0||33.5|
|Low back pain||51.6||55.0|
aDefined as having difficulties in one or more of the following areas: movement, emotional, seeing, hearing, or cognition.
bDefined as having limitations in one or more of the following areas: self-care, social, or work.
SOURCE: CDC and NCHS, 2010.
1 in 14 said this lost work time exceeded 2 hours. On average, respondents reported that their reduced performance amounted to 3.6 hours per week (Stewart et al., 2003).
The economic analysis conducted for this study found that people with severe pain missed an average of 5.0-5.9 more days of work per year than people with no pain. The components of the cost of lost productivity included days of work missed ($11.6-12.7 billion), hours of work lost ($95.2-96.5 billion), and lost wages of ($190.6-226.3 billion). (The methodology used to develop these estimates is described in Appendix C.)
Effects on Quality of Life
Severe or migraine headaches have significant personal and societal impacts. Increasing evidence suggests that people with headaches have poor health-related quality of life; they also can experience serious functional impairments as a result of the headaches themselves and their unpredictable occurrence (Kalaydjian and Merikangas, 2008). These disruptions include impaired ability to work, go to school, participate in family life, and engage in leisure activities.
Migraine often occurs in conjunction with several other physical conditions, such as asthma, epilepsy, and chronic musculoskeletal pain, as well as with mood and anxiety disorders. Adults with severe headaches/migraine are significantly more likely than those without to suffer from comorbid conditions. In one study, for example, 85 percent of headache sufferers had at least one significant physical condition, compared with 69 percent of nonsufferers, and 15 percent of those with headaches reported major depression, compared with 5 percent of nonsufferers (Kalaydjian and Merikangas, 2008). Only 18 percent of those with severe headaches rated their general health as “excellent,” compared with 27 percent of those without headaches. Research has consistently documented the relationship between migraine and poorer health-related quality of life and shown quality of life to be inversely proportional to the frequency of migraine occurrence (Terwindt et al., 2000).
These findings in adults have parallels in adolescents, with adolescents aged 13-17 with migraine reporting greater reductions in physical well-being and total quality of life relative to those with tension headaches (Milde-Busch et al., 2010). Another study that used a quality-of-life instrument designed for children (PedsQL 4.0) concluded that the quality of life of children with migraine, compared with that of healthy children, was adversely affected in all areas of functioning (physical health; psychosocial health; and emotional, social, and school functioning)—a level of impact the authors equated to that experienced by children with rheumatoid diseases or cancer (Powers et al., 2003). The significance of pain at a young age includes effects on school attendance; decreased academic performance; reduced participation in athletic and social activities; social stigma; impaired ability to establish and maintain peer relationships; sleep disturbances;
impact on quality of life; and higher levels of distress, anxiety, and depression (Lateef et al., 2009; Palermo, 2009). In addition, early pain experiences may lay the groundwork for illness or chronic pain in adulthood.
At the other end of the age spectrum, studies of older adults also find decreased quality of life for those in severe pain. For example, one study found significant differences for adults over 65 between those who had pain and those who did not with respect to satisfaction with life and health-related quality of life. More severe pain also led to social isolation (Simsek et al., 2010).
Cancer patients with current pain, compared with those without pain, reported statistically significant decreases in general health, physical functioning, and role and social functioning. Similarly, those who had had pain since their diagnosis, compared with those who had not, were less worried about the harmful effects of pain treatment and more likely to report depression, as well as every category of impact on functioning that was measured (general health and physical, emotional, cognitive, role, and social functioning), as well as additional symptoms (fatigue, trouble sleeping, loss of appetite) (Green et al., 2011).
Effects on the Risk of Suicide
The risk of suicide among people with chronic pain appears to be about double that of control groups, with the lifetime prevalence of suicide attempts by chronic pain sufferers ranging from 5 to 14 percent in various studies (Tang and Crane, 2006). Establishing a link between persistent, severe pain and suicide is complicated, however, by the need to take into account the psychological comorbidities described in Chapter 1.
A 2006 review of the literature found eight suicide risk factors for people in chronic pain. Four were specifically pain-related factors: type, intensity, and duration of pain, and insomnia. Four were psychological factors: helplessness and hopelessness about pain, the desire to escape from pain, pain catastrophizing and avoidance, and deficits in problem-solving ability (Tang and Crane, 2006).
Most research on the association between suicide and pain has taken place in clinical settings among people who had chronic pain and were
most likely not representative of the general population. Studies also have had unclear comparison groups. A recent population-based study used data on nearly 5,700 adults representative of the U.S. population to investigate pain and suicide (Ilgen et al., 2008). In this study population, 29 percent of the subjects had chronic pain, back or neck pain, frequent or severe headaches, or other nonarthritis pain. All of these conditions “were consistently related to suicidality” (p. 523), with chronic severe headaches having the strongest association. People with chronic headaches were 4.3 times more likely than those without such headaches to think about suicide, 4.6 times more likely to plan suicide, and 6.5 times more likely to have attempted suicide in the previous 12 months. Those with “other” chronic pain also were more likely than those without such pain to have thought about (2.5 times as likely), planned (3.5 times), and attempted (6.2 times) suicide (Ilgen et al., 2008).
Once these data were adjusted for other physical problems and for recent psychopathology that increases suicide risk (e.g., depression, anxiety disorders, substance abuse), the higher risk for people with pain generally remained, especially for people with multiple sources of pain. People having two or more types of chronic pain were “almost three times more likely to report a suicide attempt” (p. 523) than people without pain. The strong association between suicidality and chronic headaches remained after the adjustment described.
These findings mirror those of a recent population-based study among Canadians, which likewise found that the presence of one or more chronic pain conditions was associated with suicide ideation and attempts and that migraine had the strongest association with both, even after adjusting for mental disorders (Ratcliffe et al., 2008). In addition, the study showed that the presence of chronic pain significantly increased the association with suicide ideation and attempts among people with a mental disorder.
Clinicians serving people with multiple pain conditions and serious and persistent headaches should be aware of this heightened risk. At present, suicide prevention efforts tend to focus on people exhibiting psychiatric symptoms or recent suicide attempts, not on pain as an independent risk factor for suicide (Ilgen et al., 2008).
Finally, according to the National Violent Death Reporting System, 20 percent of all suicide deaths in 2008 in the 17 states that system monitors were among former or current military personnel. Almost 40 percent of these victims had some physical health problem believed to have played a part in the decision to commit suicide (CDC and NVDRS, undated). This data set—although the nation’s most comprehensive on the issue of suicide—does not cover all states, nor does it ask specifically about pain as a contributing factor. However, the association between self-reported pain severity and suicide among veterans has been confirmed in other research (Ilgen et al., 2010). After controlling for demographic and psychiatric characteristics, Ilgen and colleagues determined that veterans with severe pain were one-third more likely to die by suicide than those without pain or with only mild or moderate pain.
Differences in the Seriousness of Pain by Race/Ethnicity and Sex
Statistically significant differences by race/ethnicity and sex have been found with respect to the impact of cancer pain on measures related to quality of life, with diminished quality reported for both blacks and women (Green and Hart-Johnson, 2010). Past research has found that African Americans with low back injuries, compared with whites with such injuries, report higher rates of problems with physical functioning and with carrying out family/home responsibilities, social and occupational activities, self-care, and basic life-supporting activities
(Jerome and Gross, 1991; Tait and Chibnall, 2005). Even when pain affects lower percentages of blacks than whites, blacks may show higher rates of related conditions, such as depression, PTSD, or sleep disorders (Green et al., 2004).
Contrary to some other findings, a telephone survey of a nationally representative sample of 454 white (non-Hispanic), 447 African American (non-Hispanic), and 434 Hispanic adults in the United States found that the prevalence of “frequent or persistent pain” for 3 months or longer during the previous year was roughly similar across the three groups. These results contributed to “a variety of conflicting findings related to the racial and ethnic influences on the effects of chronic pain” (Portenoy et al., 2004, p. 326). Approximately a third of subjects in all three groups had “disabling pain,” which the authors defined as both of high severity and greatly interfering with daily functioning. In this study, factors with a statistically significant association with a higher likelihood of disabling pain were female sex, income under $25,000, failure to graduate from high school, and divorce. Of these, income and education were most important. Many, but not all, of the factors associated with a lower likelihood of disabling pain were the obverse of these: younger age, income over $25,000, being employed, suburban residence, and a college or graduate degree. Those at least risk of disabling pain were in the highest income group and had the most education. (See also the discussion of income and education earlier in this chapter.)
As a hypothesis to explain their finding that race did not predict the likelihood of disabling pain, Portenoy and colleagues note that “Hispanic and African American subjects were significantly more likely to have those characteristics identified as predictors of disabling pain than white subjects” (p. 325). They add, “Given the complex interactions between demography, culture, and other factors, additional studies are needed to clarify the degree to which the adverse effects10 of chronic pain can be explained by race and ethnicity or the mediating variables with which they associate” (p. 326). Undertreatment, they suggest, may be one such potential mediating variable (see the discussion of undertreatment earlier in this chapter), along with group differences in the likelihood of seeking treatment or the choice of provider (primary care versus specialist, for example), concerns about pain medications, and so on.
10 In this study, “adverse effects” included disturbed sleep, exhaustion or fatigue, inability to concentrate, loss of appetite or weight gain, or loss of sex drive; depressed mood, anxiety, irritability, or feeling stressed; and inability to work, participate in sports, do household chores, take care of family members, or socialize with friends or family.
Our current health insurance companies are dictating medication prescriptions for patients based on their own guidelines. People are suffering because they cannot afford to pay for medications out-of-pocket or the exorbitant co-pays required.
Costs to the Nation
The rising cost of health care is the greatest challenge facing the nation’s health care system and the public programs that pay for health services. Estimating the total national toll of pain on the U.S. economy is problematic, and estimating even costs within the health care component of the economy is difficult because the costs of pain are bound up with the costs of treating many other conditions and therefore difficult to disentangle. The abundant methodological challenges in calculating the costs of pain include
- how to determine the number of people with pain during a given time interval;
- how to classify types of pain, such as by body part or severity;
- how much of an increase in health care costs is attributable to pain when people with pain often present, and are simultaneously treated for, many health problems, some of which may be related to pain;
- the extent to which people with pain may be underrepresented in various data collection efforts;
- the degree to which pain contributes to missed days or hours of work and to the loss of a capacity to perform work that the person otherwise would perform;
- the degree to which pain causes work-related disabilities and the costs of managing those disabilities; and
- the costs of noneconomic impacts of pain, such as suffering, tolls on families, and children’s developmental consequences.
A regression analysis performed for this study and based on data from the MEPS for 2008 revealed that the annual cost of pain in the United States is $560-635 billion12 in 2010 constant dollars (see Appendix C). This estimate combines the
11 Quotation from response to committee survey.
12 The findings, methods, and limitations of this economic study are described in Appendix C.
incremental cost of health care ($261-300 billion) and the cost of lost productivity ($11.6-12.7 billion) attributable to pain. The $560-635 billion range is a conservative estimate because it excludes the costs of pain affecting institutionalized individuals (including nursing home residents and corrections inmates), military personnel, children under age 18, and personal caregivers (such as spouses who miss work while caring for people with pain), as well as the lost productivity of workers younger than 24 and older than 65. The estimate also excludes the emotional cost of pain. Even with these omissions, the estimate of the annual U.S. cost of pain given in Appendix C is higher than published estimates of the annual costs of heart disease, cancer, and diabetes; however, because different methods were used to derive these estimates, they are not strictly comparable. The analysis found that moderate pain, severe pain, joint pain, arthritis, and functional disability were all strongly associated with an increased probability of higher health expenditures.
Prior to this analysis, the National Institutes of Health used its own estimate, developed in the late 1990s, of $100 billion as the total U.S. cost of pain, including health care expenses, lost income, and lost productivity (NIH and NCCAM, 2010). Additionally, interesting estimates of the annual costs of several pain-related conditions have been developed by various researchers using different methodologies. These estimates include the following:
- headache—$14 billion, only $1 billion of which consists of health care costs (Hu et al., 1999), partly because most people with migraine stop seeking medical care for the condition (Silberstein, 2010);
- arthritis—$189 billion, less than half ($81 billion) of which is for health care costs (Yelin et al., 2007);
- low back problems—$30 billion (Soni, 2010);
- spine problems—$2,500 average in incremental medical costs (Martin et al., 2008);
- spine surgical procedures—$1 billion in Medicare expenditures (Dartmouth Atlas of Health Care, 2006);
- back pain—$100-200 billion in decreased wages and lost productivity (Freburger et al., 2009); and
- headache, arthritis, backache, and other musculoskeletal conditions—$61 billion (Stewart et al., 2003).
Disability from all causes has been estimated to cost $300 billion annually, with the pain-related conditions of arthritis and back/spine problems being the top two causes of disability (CDC, 2009).
A 2007 estimate of the national cost of pain also has been developed for Australia. The cost to that nation is estimated13 at US$26.8 billion, or US$1,288
13 AU$34.3 billion in 2007 (Access Economics, 2007), with a 1.28 currency exchange rate in January of that year.
per capita. In comparison, the analysis commissioned for this study found the cost of pain to be $1,842-2,072 per capita in 2008, which is 43-61 percent higher than the Australian figure. A major factor in this difference is the high cost of U.S. health care; in 2003, the per capita cost of health care was more than twice as high in the United States as in Australia (Kaiser Family Foundation, 2007).
The cost of pain to the federal government is immense. The federal Medicare program bears fully one-fourth of U.S. medical expenditures for pain. In 2008, this amounted to at least $65.3 billion, or 14 percent14 of all Medicare costs. In total, federal and state programs—including Medicare, Medicaid, the Department of Veterans Affairs, TRICARE, workers’ compensation, and others—paid out $99 billion in medical expenditures attributable to pain. Lost tax revenues due to productivity losses compound that expense (Gaskin and Richard, 2011 [see Appendix C]).
Pain prevention therefore offers the prospect of substantial savings in U.S. health care costs. The analysis conducted for this study found that on average, a person with moderate pain generates health care expenditures $4,516 higher than those for a person without pain. A person with severe pain generates health expenditures $3,210 higher than those for a person with moderate pain. The precise reasons for these large cost differences are unclear; to the extent that they reflect differential utilization of health services due to pain, however, the potential cost savings if pain were prevented or treated more effectively are enormous.
Finally, as noted previously, people with chronic pain are frequent users of complementary and alternative medicine (CAM) services. The costs of these services—which often must be paid, at least in part, out of pocket—are difficult to measure or compare with those of conventional care. Washington State, where private insurance coverage of all licensed CAM providers is mandated, offers a unique opportunity to use insurer claims data to compare costs for those who use CAM for at least part of their care and those who do not. Such a study was performed on 2002-2003 data for insured individuals with back pain, fibromyalgia, and menopause symptoms, matching 26,466 CAM users with 13,025 nonusers on a 2:1 basis. Overall, CAM users had lower average expenditures than nonusers ($3,797 versus $4,153). Their outpatient expenses were higher, but offset by lower expenses for inpatient care and imaging. People who had the heaviest disease burdens accounted for the highest levels of savings, an average of $1,420. The study findings are suggestive, but limited because they do not reveal long-term costs or health outcomes (Lind et al., 2010), and longer-term studies would help clarify these potential savings.
14 Using information provided in Appendix C, to compute the 14 percent figure, start with $261.1 billion as the low, or Model 1, estimate of medical expenditures for pain, from Table C-5. Multiply this by 25 percent as the share borne by Medicare, from Table C-6. Divide this product, $65.3 billion, by total Medicare 2008 expenditures of $465.7 billion, from Martin and colleagues (2011).
Costs to Families
The social costs of pain, especially chronic pain, affect not only the person in pain but also friends, coworkers, and especially the family. As noted by Martel (2011, p. 2), “The family is more than a collection of individuals. That is, the whole is greater than the sum of its parts. One must view the family as an entity in its own right with its own ‘life.’” And pain makes everything about that life different.
Family members find that their relationship with their loved one changes, and to the extent that they must take on new roles (as caregiver and morale booster) and greater responsibilities in the family (e.g., grocery shopping, chores, errands), the burden on them increases. They may observe not just physical but also psychological changes. Often “a person in pain withdraws emotionally from the spouse or partner and other family members. A family member’s negative reaction to this withdrawal is a natural response” (Rome, 2011, p. 1).
A pilot study involving 75 pediatric patients and their families attempted to measure the economic cost to families of having a child with serious pain (of several common types) and the effect of treatment in a multidisciplinary pediatric pain outpatient clinic (Ho et al., 2008). In the 3 months prior to treatment in the multidisciplinary clinic, the pediatric patients used a variety of physician services and received other services, such as physical therapy and mental health services, in both inpatient and outpatient visits, accumulating mean outpatient visit charges of $1,761 and mean inpatient charges of $7,020 (both with large standard deviations). This high utilization produced lost school days and lost workdays for parents. In the 6 months after enrollment in the multidisciplinary clinic, the children made fewer visits to specialists and mental health providers for their condition, had fewer x-rays, and incurred lower health care costs. All differences were statistically significant (p ≤ 0.01). Likewise, medical appointments consumed less family time and resulted in somewhat fewer missed workdays. Average outpatient care charges were reduced to $560 and average inpatient charges to $546, again with large standard deviations. The reduction in inpatient charges also was highly statistically significant (p ≤ 0.01).
In the long term, pain may change nearly every aspect of family life, and to the extent that the person in pain cannot work, the family’s financial stability may be threatened. Heightened stress may affect the children, who do not understand why their parent is withdrawn, irritable, and no longer the willing playmate of the past. One study showed that parents of children being treated in a pediatric rheumatology clinic were highly likely to have chronic pain conditions themselves and that higher levels of parental pain and related disability were reflected in higher levels of pain in the children. The parents’ pain experiences predicted the children’s reaction to their own pain and the development of maladaptive coping strategies (catastrophizing) to deal with it (Schanberg et al., 2001). This study provides a good example of how social conditions (in this case family history) affect the expression and experiences of pain.
At the same time, continued emotional support is vital to the functioning of a family member in pain and to aiding in his or her rehabilitation. People who report family disharmony and lack of support do not benefit from pain treatment to the same extent as those with strong family support (Jamison and Virts, 1990). In one study, for example, those who reported having nonsupportive families were more likely to have work-related injuries; to rely on medication; and to report more pain sites, more pain behavior, and more emotional distress. By contrast, people with supportive families reported significantly less pain intensity, needed less medication, and were more active (Jamison and Virts, 1990).
Public health policy and practice, directed at primary prevention of chronic pain in populations, offers the potential to reduce the frequency of chronic pain and the impact it has on societies.
—Croft et al., 2010, pp. 353-354
This chapter has described how widespread acute and chronic pain is in the United States, affecting large segments of the population. It also has shown that pain affects subgroups of the population differently and not always as conventional wisdom might suggest. It has made clear that serious pain has significant effects on people’s daily activities, disability, and quality of life and is linked to suicide. It further has shown that pain is exceedingly costly in terms of both direct health care costs and the indirect costs associated with disability, lost employment, and reduced income.
The beginning of the chapter presented eight rationales for regarding pain as a public health issue. For three of these—the extent of the problem, its differential impact on vulnerable population groups, and its costliness—the evidence discussed in this chapter is strong and persuasive. (The rationales related to problems with opioids, training, and research are discussed in Chapters 3, 4, and 5, respectively.) This section addresses the remaining two rationales—the need for prevention and for multimodal efforts—and the associated roles for public health, as well as some additional potential public health contributions.
Perhaps the most important conclusion that can be drawn from a review of the enormous toll caused by pain relates to the need for prevention. A public health approach to prevention attends to the external, often structural, factors in the social and physical environments that affect not just individuals but popula-
tions. These are the “upstream” influences that shape conditions and behaviors that produce or exacerbate disease.
In many instances, pain prevalence could be reduced as a consequence of normal public health initiatives aimed at preventing chronic disease, injuries, and violence and promoting healthy weight, dental care, and so on—factors associated with ameliorating health problems. A prevention approach to pain, for example, would consider conditions in the work environment that contribute to back and other musculoskeletal injuries or promotion of the use of safety helmets and goggles to reduce sports injuries. It would create effective preventive systems to enable prompt response to risk factors that suggest acute pain is evolving into chronic pain. It would support the development of community-wide understanding of the nature of pain and factors that increase it so that individuals would receive the assistance they need at the right time. A public health approach also would engender organizational, professional, and personal actions to avoid reinjury and loss of self-efficacy, as well as other measures to protect health.
As suggested at the beginning of this chapter, a comprehensive public health approach to preventive measures such as these would involve people in many sectors, including health care leaders and clinicians, the individuals affected by pain and their families, disease and child advocates, academic leaders, employers, social marketers, policy makers, union leaders, workers’ compensation program directors, and insurance executives. As with all preventive efforts for which it is difficult to document impact on events that “do not occur,” a direct link between efforts to reduce the occurrence of specific diseases and injuries and thereby the prevalence of pain will be difficult to establish. Nevertheless, epidemiologists and economists can help in the planning stages of such public health programs to design data collection strategies that will fill some gaps in understanding of where best to target pain-prevention efforts.
In addition to general prevention programs aimed at avoiding illness and injury (of which pain is one consequence), the kinds of educational programs and behavior change support programs that are a mainstay of public health activities are obvious targets in the primary prevention of pain. Some successful examples are briefly described in Box 2-4.
Public health entities have a role in prevention because of the high utilization of publicly funded service delivery programs, such as community service programs, public housing, rural and migrant health centers, services for the homeless, the IHS, and the Native Hawaiian Health Care Systems Program. Together, these public programs serve nearly 20 million people a year. These programs, which typically serve groups at high risk for pain and its consequent disability, should provide comprehensive, interdisciplinary, state-of-the-art pain care.
Aside from its role in direct service delivery, the public health establishment reimburses for care in nonpublic settings, including hospitals, doctors’ offices, and pharmacies. Together, federal, state, and local governments accounted for
Examples of Population-Based Prevention Initiatives
Prescription Drug Take-Back Programs
These programs (for example, the Drug Enforcement Administration’s [DEA’s] Nationwide Prescription Drug Take-Back Day and Utah’s Use Only as Directed campaign) are intended to reduce the misuse and abuse of prescription pain medications. These efforts combine media and other educational efforts to promote safe use, storage, and disposal of potentially dangerous drugs, and include opportunities for the public to return “expired, unused, and unwanted prescription drugs” to collection centers.a According to the DEA, during a Take-Back Day held in September 2010, Americans turned in more than 121 tons of prescription drugs to state and local law enforcement partners (DEA, 2011). Although such programs do not directly affect pain prevalence, the rising rates of opioid use may lead to policy and enforcement practices that make these medications less available to people who need them.
Campaign to Reduce Back Pain Disability
A 3year campaign in Victoria, Australia, in the late 1990s (described in more detail in Chapter 4)—Back Pain, Don’t Take It Lying Down—used mass media and other means to promote several evidence-based concepts, including that disability can be improved by positive attitudes, that people with back pain should continue to participate in their usual activities, and that they can do much to help themselves. The campaign aimed to reach both the general public and health care professionals. Evaluation revealed dramatic improvements in what the public and clinicians believed about back pain, accompanied by a decline in related workers’ compensation claims and health care utilization during the campaign; those beliefs have persisted over time (Buchbinder, 2010).
A 2002 Institute of Medicine study found that since the 1980s, there have been a wide range of suicide prevention initiatives taking a population-based approach (IOM, 2002b). Examples include improved prevention programs in schools, research on programs to target high-risk people, and efforts to identify broader patterns of suicide and suicidal behavior in groups or populations. As discussed earlier in this chapter, chronic pain and depression, as well as other emotional disorders, often go hand in hand, and all of these conditions may increase the likelihood that a person has available prescription drugs that could be used for suicide. Some measures designed to protect the population at large, such as limiting the size of prescriptions, may have unintended consequences for people with chronic pain.
aThe Secure and Responsible Drug Disposal Act of 2010 allows people to dispose of controlled-substance medications by delivering them to authorized entities.
43 percent of national health expenditures in 2009 (Martin et al., 2011). Developing or disseminating guidelines on pain care, creating partnerships with professional societies and advocacy groups, developing quality standards around pain management, and requiring pain care content in graduate medical education and continuing education programs all can be used to improve the clinical care of people with pain and prevent the related disability and other negative consequences of inadequate care.
The rules and practices governing both service delivery and payment programs, including any changes or coverage expansions that grow out of health reform and “meaningful use” requirements for electronic health records, should be aligned with the best thinking about pain management and disability prevention. They should ensure that federally funded health services programs are supporting coordinated, consistent care across needs and helping people develop the self-care and family care skills that may improve results and quality of life. Achieving this will be challenging for geographically isolated rural and IHS providers, however, especially in the face of state and federal budget cuts.
Support for Multimodal Efforts
As suggested at the outset of this chapter, much more than conventional medical care is involved in the public health approach to health promotion and disease prevention for the population. Public health considers the systematic differences in health status and outcomes and tries to “identify and understand the factors leading to poorer outcomes” (Russo, 2011, p. 86). The multiple determinants of health in the population health model are in five interacting categories: the social and economic environment, the physical environment, genetics, medical care, and health-related behavior (Russo, 2011). With respect to pain specifically, these five factors affect not only the likelihood of experiencing pain but also the likelihood that it will progress to a chronic condition, the amount of disability that will result, and the specific needs a person (and family) will have. For example, the diverse array of public and private agencies that work to identify and prevent child abuse and sexual abuse and aggressively treat children exposed to traumatic events (including violence) can be important not only in preventing pain during childhood but also in preventing the potential occurrence of chronic pain when these children reach adulthood (NIH and NICHD, 2002).
Public entities that provide or fund health services (for example, community health centers, the Medicaid program, state mental hospitals) for people in high-risk groups must ensure that their programs effectively manage pain and that referrals to more specialized community pain resources are made appropriately. Medicare policy should encourage aggressive team management of difficult pain conditions. Special efforts should be made to ensure that state workers’ compensation programs are handling claims in timely and effective ways most likely to resolve painful injuries and return people to work and normal activities.
In addition, a substantial amount of health professions education is funded through state and federal government programs—particularly graduate medical education (residency programs). State governments are in charge of setting licensing and credentialing standards for the major health professions. Although curriculum changes are notoriously difficult to achieve, public agencies can influence training institutions to increase the quality and quantity of educational content relating to pain.
Other Public Health Contributions
Several roles for public health entities in addressing the problem of pain exist beyond those described above. One such role would involve CDC, the Substance Abuse and Mental Health Services Administration, the FDA, and federal and state law enforcement agencies in reconciling the competing goals of effective pain management and avoidance of the harmful effects of opioids. This issue should be addressed within the public health structure; involve all interested parties; and be communicated clearly to health care providers, people with pain, and the public.
CDC, AHRQ, and other agencies are involved in data gathering with respect to the prevalence of pain conditions, their treatment, their costs, and resultant disability. Their information systems can be used not only for surveillance but also analytically to identify groups at greatest risk of complications for purposes of targeting interventions. They can contribute to the collection of longitudinal data on the various consequences of serious pain; the related conditions (physical and mental) common in people with pain; the progression of acute to chronic pain; and consequences over time for subgroups of the population, including children, with attention to the risk and resilience factors that influence the progression to adult pain. In addition, the current efforts of these agencies could be better defined, more current, and more consistent across data sets.
Additionally, CDC and other agency experts in health care communication might employ their skills in reaching underserved and vulnerable populations to disseminate useful messages about pain prevention, management, and self-care. Another area for prevention could be to determine whether over-the-counter pain medications require greater monitoring, regulation, or more public education with respect to the potential hazards of long-term use and the risk of interactions with other medications.
Finally, opportunities for a range of research programs involving the National Institutes of Health, the FDA, and other HHS agencies are discussed in Chapter 5. Their aim should be to support discovery through a spectrum of research and demonstration initiatives to determine the most effective strategies for reducing the disruption and the personal, financial, and social costs of pain, especially in the most vulnerable subgroups of the U.S. population.
Potential Savings from Improvements in Pain Prevention, Care, Education, and Research
Significant savings may arise through
- better treatment of acute pain, through education about self-management and better clinical treatment, in order to avoid the progression to chronic pain, which is more difficult and more expensive to treat and generates high health care utilization;
- reductions in health problems and complications of other physical and mental diseases and conditions associated with chronic pain that also are expensive to treat;
- reductions in public- and private-sector economic costs, such as workers’ compensation, lost productivity, and lost tax revenues, and the inestimable costs to families;
- prevention of some of the costly effects of pain, as public health measures and patient and public education begin to bear fruit;
- more cost-effective care of people with chronic pain when self-management and multimodal approaches are used more often, primary care physicians are educated and empowered to treat most people with pain appropriately, and unnecessary diagnostic tests and procedures and referrals to specialists are avoided;
- a reduced burden of opioid misuse and abuse as other medications are used more effectively and appropriately, and other forms of treatment successfully supplement medication use; and
- better tailoring of treatment to individuals based on new research findings and integration of those findings into patterns of care.
Costs and Savings from a Public Health Approach
A comprehensive public health approach to improving pain research, care, and education will require some new expenditures, but these costs can be offset by concomitant savings not only in reduced human suffering, but also in “hard dollars” from multiple sources. These potential savings are described in Box 2-5.
Finding 2-1. Pain is a public health problem. Pain is a significant public health problem. Chronic pain alone affects approximately 100 million U.S. adults. Pain reduces quality of life, affects specific population groups disparately, costs society at least $560-635 billion annually (an amount equal to about $2,000 for everyone living in the United States), and can be appropriately addressed through population health-level interventions.
Finding 2-2. More consistent data on pain are needed. While it is known that pain affects millions of Americans, the committee acknowledges the lack of consistent data with which to describe the nature and extent of the problem or to identify subpopulations that will benefit most from future interventions. Improvements in state and national data are needed to (1) monitor changes in the incidence and prevalence of acute and chronic pain; (2) document rates of treatment or undertreatment of pain; (3) assess the health and societal consequences of pain; and (4) evaluate the impact of related changes in public policy, payment, and care. Pain data need to be based on standardized questions, preferably using existing international standards, to facilitate comparisons over time and across populations. These data would be useful for a wide range of stakeholders, including policy makers, health care providers, health professions educators, professional licensing authorities, pain advocacy and awareness organizations, and researchers.
Recommendation 2-1. Improve the collection and reporting of data on pain. The National Center for Health Statistics, the Agency for Healthcare Research and Quality, other federal and state agencies, and private organizations should improve and accelerate the collection and reporting of data on pain. Data should be collected in the following domains:
- the incidence and prevalence of pain;
- interference with activities of daily living and work, as well as disability, related to pain;
- utilization of clinical and social services as a result of pain;
- costs of pain and pain care, including indirect costs of lost employment and public- and private-sector costs for disability payments; and
- the effectiveness of treatment in reducing pain and pain-related disability, determined through research on the comparative effectiveness of alternative treatments (including in different patient populations), to identify people most likely to benefit (or not) from specific treatment approaches.
Standardized questions, fields, and protocols for surveys and electronic health records should be developed, and pain-related data should be collected at regular intervals. Collection of these data will help identify subpopulations at risk for pain and undertreatment of pain; characteristics of acute and chronic pain; and the health consequences of pain in terms of morbidity, mortality, and disability, including related trends. If electronic health record systems include adequate and appropriate pain-related questions, their broader implementation will be able to facilitate the collection of consistent pain data across health care settings. Such data will help fill gaps in current knowledge regarding the prevalence,
seriousness, and trajectories of pain, as well as the effectiveness of pain treatments. This information can guide decision makers, including public and private payers, and foster more efficient and effective pain care.
Finding 2-3. A population-based strategy for reducing pain and its consequences is needed. The committee finds that, to effect changes that will reach the millions of American adults living with pain, account for differences in the experience of pain among population groups, and address selected environmental factors that contribute to the consequences of pain, a population health-level strategy is needed. A comprehensive and coordinated strategy would
- encourage and foster the prevention of pain;
- heighten national concern about pain as a health care quality and safety issue;
- use public health communication strategies to ensure that patients understand their role in managing their own pain;
- identify and attempt to remediate relevant environmental factors, especially those that adversely affect children and start them on a path to chronic pain as adults; and
- inform members of the public about what chronic pain is, how they can help loved ones who have it, and how they may be able to help prevent it for themselves and others.
Recommendation 2-2. Create a comprehensive population health-level strategy for pain prevention, treatment, management, and research. The Secretary of the Department of Health and Human Services should develop a comprehensive, population health-level strategy for pain prevention, treatment, management, education, reimbursement, and research that includes specific goals, actions, time frames, and resources. This strategy should
- Describe how efforts across government agencies, including public–private partnerships, can be established, coordinated, and integrated to encourage population-focused research, education, communication, and community-wide approaches that can help reduce pain and its consequences and remediate disparities in the experience of pain among subgroups of Americans.
- Include an agenda for developing physiological, clinical, behavioral, psychological, outcomes, and health services research and appropriate links across these domains (consistent with Recommendations 5-1 through 5-4).
- Improve pain assessment and management programs within the service delivery and financing programs of the federal government.
- Proceed in cooperation with the Interagency Pain Research Coordinating Committee and the National Institutes of Health’s Pain Consortium and reach out to private-sector participants as appropriate.
- Involve the following agencies and entities:
- Federal agencies and departments
- National Institutes of Health
- Centers for Disease Control and Prevention
- Food and Drug Administration
- Centers for Medicare and Medicaid Services
- Agency for Healthcare Research and Quality
- Health Resources and Services Administration
- Indian Health Service
- Department of Defense
- Department of Veterans Affairs
- Private-sector entities
- Pain advocacy and awareness organizations
- Health professions associations
- Health care providers (e.g., accountable care organizations)
- Health professions educators, colleges, and training programs
- Private insurers
- Accreditation (e.g., Joint Commission, National Committee for Quality Assurance), certification (e.g., American Board of Medical Specialties), and examination (e.g., National Board of Medical Examiners) organizations
- State-level entities
- Health professions licensing authorities
- Workers’ compensation programs
- Medicaid programs
- State health departments.
- Include ongoing efforts to enhance public awareness about the nature of chronic pain and the role of self-care in its management.
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