This chapter begins by describing what is known about the linkages between fatigue and health. Following a brief summary of the medical certification of the health of commercial motor vehicle (CMV) drivers, the discussion turns to a medical condition that has been the subject of a great deal of attention with respect to the health of CMV drivers and the implications for highway safety—obstructive sleep apnea (OSA). The discussion addresses OSA among CMV drivers, the association of severe OSA with increased crash risk, treatment of OSA with positive airway pressure (PAP) devices, and medical examination policy for drivers regarding OSA. Next, the chapter reviews non-OSA medical conditions among CMV drivers and the linkages between lifestyle factors and drivers’ health. The final section reviews current fatigue and health and wellness management programs for CMV drivers.
As mentioned in the statement of task for this study (see Box 1-1 in Chapter 1), the panel was to “assess the relationship of these factors [hours of driving, hours on duty, and periods of rest] to drivers’ health over the longer term.”
A substantial evidence base supports the fundamental relationship between sleep needs and health risks. According to the report Sleep Disorders and Sleep Deprivation: An Unmet Public Health Problem (Institute of Medicine, 2006), “The cumulative long-term effects of sleep loss and sleep disorders have been associated with a wide range of deleterious health consequences including an increased risk of hypertension, diabetes, obesity, depression, heart attack, and stroke. After decades of research, the case can be confidently made that sleep loss and sleep disorders have profound and widespread effects on human health.” In its Mortality and Morbidity Weekly Report of March 4, 2011 (Buxton et al., 2010; Strine and Chapman, 2005), the Centers for Disease Control and Prevention (CDC) states, “Sleep impairment is linked as a contributing factor to motor vehicle crashes, industrial disasters, and medical and other occupational errors. Persons experiencing sleep insufficiency are more likely to have chronic diseases such as cardiovascular disease, diabetes, depression, or obesity.” Further, a recent survey by Czeisler (2015) summarizes the linkages between fatigue and many of the health problems exhibited by truck and bus drivers:
. . . in the 15 years since Eve Van Cauter and her colleagues at the University of Chicago discovered that sleep deficiency adversely impacts metabolic and endocrine functions, it has been demonstrated unequivocally that the duration, timing, and quality of sleep also critically affect physical health, mental health, performance, and safety. Thus it is clear that sleep is critical not just for optimal brain functioning but also for optimal functioning of the body as well. . . .
Rigorous physiological studies have demonstrated that just a week or two of sleep curtailment increases appetite and food intake, decreases insulin sensitivity and glucose tolerance, . . . degrades the ability to resist infection, disturbs mood, increases the vulnerability to attentional failures, and when combined with prior chronic circadian disruption, impairs pancreatic β-cell responsiveness. Concurrently, epidemiologic studies have revealed that habitually short sleepers have an increased prevalence of obesity; . . . that habitually short and habitually long sleepers are at increased risk for incident calcification of the coronary arteries, incident coronary heart disease, incident type 2 diabetes, incident stroke, and death. . . . During the same time interval, emerging evidence that chronic exposure to recurrent disruption of sleep and circadian timing induced by night shift work increases the risk of breast cancer, endometrial cancer, colorectal cancer, and prostate cancer. . . . Moreover, extended duration (> 24 hours) work shifts have been associated with poorer performance on clinical tasks, and increased risks of serious medical errors, preventable adverse events, self-inflicted percutaneous injuries, and motor vehicle crashes among resident physicians.
. . . Epidemiologic studies reveal that night shift work is associated with increased odds of obesity; a 5-fold increase in the risk of progressing from impaired glucose tolerance to diabetes; an increased risk of blood pressure elevation; incident hypertension; incident coronary heart disease, including fatal and nonfatal myocardial infarctions; and that a decade of exposure to shift work chronically impairs cognition.
It is important to be clear that the causal arrow can go in both directions, with fatigue raising the risks of many health problems and some health problems raising the risks of fatigue. To take an important example, as Czeisler (2015) argues, fatigue may increase the risk of obesity, and obesity can increase the potential for OSA, which can cause fatigue. Further, it is obvious that some obesity is not caused by fatigue, and some fatigue is not caused by obesity. For example, the unhealthy work conditions of many truck driving situations can lead to adverse health consequences, including obesity, which can occur regardless of whether drivers obtain sufficient sleep. More generally, the precise degree to which a shortage of sleep results in poor health or poor health leads to a shortage of sleep is unknown. The key point is that the two have an important interaction. This interaction warrants examining what efforts are being made to educate truck and bus drivers about these linkages and to motivate them to make changes that can reduce the incidence of these various health problems. Further, it is of particular interest in the present context to consider how such interventions can be evaluated.
Conclusion 1: Insufficient sleep can increase the risk of developing various health problems, including obesity, diabetes, hypertension, and cardiovascular disease, all of which can impact an operator’s level of alertness while driving and potentially impact crash risk.
An unhealthy driver behind the wheel of a commercial motor vehicle compromises the safety of the driver and general public. To address this issue, the Federal Motor Carrier Safety Administration (FMCSA) requires that CMV drivers operating in interstate commerce maintain a current medical examiner’s certificate to drive. CMV drivers must be examined at least every 2 years by a certified medical examiner to ensure that they are fit to operate their vehicle without risk of sudden or gradual impairment or incapacitation. Following this medical exam, the medical examiner can certify the driver for up to 2 years, disqualify the driver, or impose various intermediate actions.
Medical examiners follow a set of 13 federal medical standards when conducting the medical exam.2 Of these 13 standards (which have been in effect, with only minor changes, since 1971), the following 4 result in suspension of the commercial driver’s license (CDL) unless the driver has been granted an exemption by FMCSA: (1) insulin-requiring diabetes, (2) seizures requiring the use of antiseizure medication, (3) vision requirements, and (4) hearing requirements. The certification determinations for the other 9 standards are left to the discretion of the medical examiner. Certification determinations for certain medical conditions also are left to the discretion of the medical examiner, with FMCSA offering guidance on many such conditions. The difference between medical standards/regulations and medical guidelines is that medical standards must be met by CMV drivers and are to be verified by the medical examiner, whereas medical guidelines (including advisory criteria and medical conference reports) are suggestions for best practices to be utilized by the medical examiners. Medical standards and medical guidance issued by FMCSA are included in the Medical Examiner Handbook, the primary reference tool for medical examiners (see the discussion of this and other resources in the next section).3
OSA is a health condition in which the airway becomes partially blocked during sleep, resulting in frequent awakenings. As a result, the person experiences daytime sleepiness. OSA is linked to other medical conditions, such as diabetes and various cardiovascular diseases (see Surani, 2014). Its severity is judged using the apnea-hypopnea index (AHI), which measures the number of awakenings or hypopneas one experiences per hour of sleep (Ruehland et al., 2009). According to Snyder (2013), “Mild OSA is present when the AHI is between 5 and 15 and OSA symptoms exist. This means the person has episodes of delayed breathing five to fifteen times in an hour. Many people with AHIs in this range have no symptoms at all. Moderate OSA is defined as an AHI between 15 and 30,
2 The 13 standards can be found at https://www.fmcsa.dot.gov/regulations/title49/section/391.41 [March 2016].
3 Until recently, medical examiners had the FMCSA-issued Medical Examiner Handbook, as well as Frequently Asked Questions and interpretations of the regulations. The Medical Examiner Handbook was removed from the FMCSA website in early 2015 for update, although most examiners still use it as a resource. Examiners can also refer to recommendations of the Medical Expert Panel on Obstructive Sleep Apnea and the Medical Review Board (MRB), although these recommendations have not been adopted or accepted by FMCSA. The MRB, established in 2006 by FMCSA, comprised several practicing physicians, chosen from a field of many qualified candidates, with a wide variety of expertise and experience.
regardless of the presence of symptoms, while an AHI greater than 30 is termed severe OSA.” It should be noted that these categorizations are arbitrary and are unrelated to a specific degree of performance impairment.
Pack and colleagues (2002) measured a random sample of CDL holders within 50 miles of the University of Pennsylvania and found that 17.6 percent had mild OSA, 5.8 percent had moderate OSA, and 4.7 percent had severe OSA. A study by Berger and colleagues (2012) involved administering a computer-based screening instrument to 19,371 drivers across three trucking firms, 5,908 (30%) of whom were classified as at high risk for OSA. Of those, a random 2,103 underwent polysomnography, and 68 percent of them had an AHI greater than 10. This finding suggests that at least 20 percent of CMV drivers (.68 × 5,908/19,371) have at least mild OSA. What is more difficult to establish is the extent to which varying degrees of OSA are associated with different degrees of impaired performance for CMV drivers.
Increased Risk of Crashes for Commercial Motor Vehicle Drivers with OSA
A substantial research literature supports the conclusion that severe OSA—that is, OSA with an AHI over 30—is associated with increased crash risk for the nonprofessional driver. Some of the major contributors to this literature include Aldrich (1989), Findley et al. (2000), George and Smiley (1999), Teran-Santos et al. (1999), and Wu and Yan-Go (1996). (See Smolensky et al.  for a summary of studies analyzing the relationship between OSA and frequency of crashes.) The reason for this increased crash risk is that OSA causes cognitive dysfunction, due largely to sleep fragmentation (Bedard et al., 1993; Day et al., 1999; Deaconson et al., 1988; Drummond et al., 2000; Feuerstein et al., 1997; Kaneko et al., 2003; Kim et al., 1997).
Besides fatigue, the cumulative effects on the brain of chronic repeated nocturnal hypoxic episodes may cause irreversible cognitive deficits (Bedard et al., 1993; Nowak et al., 2006). Evidence indicates that some individuals with OSA are unaware of their cognitive impairment or even of being drowsy (Dement et al., 1978; Engleman et al., 1997). Several studies have shown little or no correlation between an OSA patient’s perception of sleepiness and motor vehicle crash history (Barbe et al., 1998; Horstmann et al., 2000; Teran-Santos et al., 1999; Yamamoto et al., 2000; Young et al., 1997). Because of this lack of insight, these individuals are less likely to restrict themselves from driving than drivers who are more aware of being drowsy, despite being at increased risk for a crash.
Tregear and colleagues (2009b) performed a systematic review and meta-analysis of 18 studies drawn from seven databases described in
those sources. Two of these 18 studies examine the association between OSA and crash risk for CMV drivers, while the rest are focused on passenger car drivers. Nine of the studies provide data on the relative incidence of crashes among comparable individuals with and without the disorder. Pooling of these data revealed that the mean crash risk ratio associated with OSA was likely to fall within the range of 1.30 to 5.72. Thus, if the underlying crash risk for a driver is 0.08 crashes per person-year, the crash risk for a driver with OSA can be expected to be in the range of 0.10 to 0.46 crashes per person-year. A series of sensitivity analyses was used to establish the robustness of these results to various assumptions. While the quality of the individual studies is not high, the data are qualitatively consistent, making it unlikely that future studies will contradict the finding that nonprofessional drivers with OSA are at increased risk for a motor vehicle crash. The strength of this conclusion results from the different environments and situations tested and methods used.
The question then is whether there also is an increased risk for crashes among CMV drivers with severe OSA (and what that increased risk is). A finding regarding CMV drivers reported by Tregear and colleagues (2009b) is that as “a group, drivers with OSA are at an increased risk for a motor vehicle crash when compared with comparable drivers who do not have the disorder even though a precise estimate of the magnitude of this increased risk could not be determined.” An argument might be made that definitive proof of an elevated crash risk among CMV drivers with OSA of a given hypopnea level can come only from a randomized controlled trial examining whether untreated OSA is associated with a higher risk of crashing. Such a study, however, is not feasible; it would also be unethical. Once professional drivers have been diagnosed with OSA, they must initiate treatment by using a PAP device, or they cannot continue driving. Therefore, professional drivers with OSA cannot legally or ethically be tested on the open road unless their OSA is addressed. (Such studies could be conducted in driving simulators with, say, a 2-week confinement, in which the drivers’ sleep environment and schedule were controlled; see O’Neill et al. .) The same barriers would forbid the testing of CMV drivers with OSA to assess the benefits of PAP devices in reducing crash risk.
There are reasons to believe that nonprofessional and CMV drivers would differ in their response to OSA. They certainly are different populations of drivers and faced with different tasks, so the hypothesis that CMV drivers with OSA are not at increased risk needs to be considered seriously. Professional drivers may take more naps when needed, they may orient their schedules to allow for more rest, they may ingest greater amounts of caffeine, or they may avoid congested areas when they feel tired. On the other hand, CMV drivers often drive longer hours and often
are older than the average noncommercial driver studied. Evidence also suggests that, relative to noncommercial drivers, they suffer from more ailments that could increase their degree of fatigue. Evidence that could be used to reject the notion that there is a difference between the two categories of drivers would support the hypothesis that the findings for nonprofessional drivers of passenger cars can be transferred to professional drivers of trucks and buses. Conversely, evidence that professional drivers take actions such as those cited above more often or more effectively relative to nonprofessional drivers would support the notion that there is no increased risk of crashes among the former group.4
The panel did not find credible evidence that actions to counter fatigue are taken more often or more effectively by CMV drivers. However, an unpublished study by Schneider National found that the crash frequency among drivers using PAP devices was reduced compared with their previous crash record.5 In addition, literature on somewhat analogous populations, such as railroad engineers, those in charge of ships, and airline pilots, provides evidence that OSA is a factor in increased risk of mistakes and that use of PAP devices reduces that risk (see, e.g., Quan and Barger, 2015).
Finally, it can be argued that the absence of proof is not proof of the converse. Unless good studies show that CMV drivers with severe OSA are not at increased risk of crashes, it is a principle of preventive medicine and a reasonable precaution to accept that the parallel work among general drivers applies to CMV drivers as well. Increasingly, observational science is being held to an impossible standard—either it is proven that the adverse event occurs in the “exact” population of interest, or there is considered to be no proof. The panel believes many preventable losses will be suffered if a very narrow view of what constitutes an evidence base is used to argue that only evidence that is direct and not indirect is sufficient.
The panel notes that the relationship between degree of OSA and increase in crash risk is likely represented by a smooth response curve, such that those drivers with mild OSA have little or no greater risk of crashes than drivers without OSA. Therefore, it would be extremely helpful if in the future, the research literature could be more precise about the level of OSA being considered.
4 The severity of the crash is a factor that can impact findings on the association between OSA and crash risk. Stevenson and colleagues (2014) carried out a case-control study using survey questionnaire data and found that OSA was not associated with nonfatal, nonsevere crashes.
5 Presentation by Don Osterberg, Schneider National to the Panel on Research Methodologies and Statistical Approaches to Understanding Driver Fatigue Factors in Motor Carrier Safety and Driver Health in Washington, D.C., on May 28, 2014.
Conclusion 2: Based on the evidence on drivers who are not commercial motor vehicle drivers, obstructive sleep apnea is known to increase crash risk, and there is no evidence base or compelling reason for thinking that the same would not also be true among commercial motor vehicle drivers.
Treatment for OSA
The only treatment for OSA besides weight loss that has shown widespread efficacy is the use of positive airway pressure (PAP) devices. For nonprofessional drivers with OSA, use of such devices is associated with a reduced risk of crashes compared with those with OSA who do not use such devices (Cassel et al., 1996; Findley et al., 2000; George and Smiley, 2001; Tregear et al., 2009b). A key question, then, is whether the use of PAP devices also reduces the risk for CMV drivers, and if so, to what extent?
As in the case of linking OSA and crash risk, while studies linking PAP use to decreased crash risk have some limitations, the panel believes the finding of reduced risk for nonprofessional drivers can be strongly supported. However, there is not a substantial literature directly showing that the same assertion can be made for CMV drivers (with a given degree of hypopnea).
Conclusion 3: Better understanding is needed of the effects of treating obstructive sleep apnea in commercial motor vehicle drivers with positive airway pressure (PAP) therapy with respect to the amount and quality of sleep they obtain and their cognition and driver performance following PAP treatment sessions.
A major complication is that acceptance of and adherence to PAP therapy is a problem for many patients (Kribbs et al., 1993; Weaver et al., 1997). Moreover, the amount of PAP use needed to produce clinically meaningful improvements in real-world sleep, cognition, and behavior remains unclear (Gay et al., 2006).
Medical Examination Policy Regarding OSA
FMCSA’s current medical examination policy for CMV drivers states, “A person is physically qualified to drive a motor vehicle if that person has no established medical history or clinical diagnosis of a respiratory dysfunction likely to interfere with his/her ability to control and drive a motor vehicle safely.” Thus if the medical examiner detects a respiratory dysfunction that in any way is likely to interfere with the driver’s ability to control and drive a commercial motor vehicle safely, the driver must
be referred to a specialist for further evaluation and therapy before being certified. While no regulation specifically mentions OSA, it would be covered under this respiratory standard.
In 1998, OSA was first mentioned in the advisory criteria for the respiratory standard:
There are many conditions that interfere with oxygen exchange and may result in incapacitation, including emphysema, chronic asthma, carcinoma, tuberculosis, chronic bronchitis and sleep apnea. . . .
Medical examiners could find minimal guidance on OSA in a 1991 Conference on Pulmonary/Respiratory Disorders and Commercial Drivers (Turino et al., 1991), sponsored by the Office of Motor Carriers, a predecessor of FMCSA. The experts on that panel recommended that if there were any suspicion that a driver had OSA, the driver should be evaluated and the condition successfully treated before the driver returned to work. Medical examiners were offered no specific criteria for having concern or suspicion that a driver was at risk of having OSA. The conference participants recommended at least a 1-month waiting period after treatment for OSA had been initiated before a driver returned to commercial driving. They also advised evaluation of the effectiveness of treatment through either multiple sleep-latency testing (MSLT) or polysomnography. They recommended further that drivers with OSA who were medically qualified to drive commercial motor vehicles be reevaluated annually by means of sleep studies or MSLT.
The 1991 conference report was not widely disseminated, and the majority of medical examiners likely were unaware of its existence. In 2000,6 the examination form used to evaluate CMV drivers was updated and for the first time included a specific question on OSA, asking the driver to indicate “yes” or “no” with respect to “sleep disorders, pauses in breathing while asleep, daytime sleepiness, loud snoring.” When this form was first issued, many drivers responded “yes” to this question, and examiners reported that they either asked these drivers to provide documentation from their treating provider or referred the drivers for further evaluation. By the second year of use of this form, examiners indicated that few drivers checked “yes” for this question.
In preparation for the National Registry of Certified Medical Examiners (NRCME), FMCSA compiled the Medical Examiner Handbook from
6 U.S. Department of Transportation Federal Motor Carrier Safety Administration. (2000). Final rule. Physical qualification of drivers; medical examination; certificate. Federal Register, 65(194), 59363-59380. Available: http://www.gpo.gov/fdsys/pkg/FR-2000-10-05/pdf/0025337.pdf [March 2016].
existing guidance drawn from various FHWA (or FMCSA)-sponsored panels, frequently asked questions (FAQs), advisory criteria, and regulatory guidance. The section with information on OSA was the last section posted—not until fall 2010—and was not significantly different from what had been in the 1991 conference report.
The Medical Examiner Handbook indicated that examiners “should not certify the driver with suspected or untreated sleep apnea until etiology is confirmed and treatment has been shown to be stable, safe, and adequate/effective,” but still offered no specifics on how to identify drivers suspected of having OSA. Additional guidance for examiners had been provided in three FAQs on the FMCSA website addressing sleep disorders. FMCSA also had a section of its website devoted to sleep apnea, “Spotlight on Sleep Apnea,” with information for drivers and carriers, but no information on screening, diagnosis, or treatment. In early 2014, to comply with Public Law 113-45,7 FMCSA removed the section of the Medical Examiner Handbook on OSA, the FAQs on sleep disorders, and “Spotlight on Sleep Apnea” from the FMCSA website. In early 2015, as noted earlier, the entire Medical Examiner Handbook was removed from the FMCSA website for revision.
There have been several efforts to develop criteria that examiners could consider for identifying drivers at highest risk of having OSA. In 2006, a Joint Task Force of the American College of Occupational and Environmental Medicine, the American College of Chest Physicians, and the National Sleep Foundation recommended OSA screening criteria for drivers (Hartenbaum et al., 2006). In 2007 and 2008, based in part on an FMCSA-supported evidence report (updated in 2011) (Williams et al., 2011), FMCSA’s Medical Expert Panel on Obstructive Sleep Apnea and Commercial Motor Vehicle Driver Safety (MEP) (Ancoli-Israel et al., 2008) and Medical Review Board (MRB) (Federal Motor Carrier Safety Administration Medical Review Board, 2008) developed recommendations, referenced earlier, that would have required testing a larger percentage of drivers than the Joint Task Force had proposed.8 In 2012, the Motor Carrier Safety Advisory Committee (MCSAC), an industry advisory group, and the FMCSA MRB offered joint recommendations (Federal Motor Carrier Safety Administration Medical Review Board, 2012).
FMCSA did not adopt the three sets of recommendations described in the previous paragraph. Examiners therefore continue to vary in how
7 Public Law No. 113-45 Commercial Motor Vehicle Operator Requirements Relating to Sleep Disorders. Signed by President Obama October 13, 2013. Available: http://www.gpo.gov/fdsys/pkg/PLAW-113publ45/pdf/PLAW-113publ45.pdf March 2016].
8 The need to require testing of a larger percentage of drivers than proposed by the Joint Task Force would have been linked to the establishment of more stringent criteria (e.g., lowering the body mass index [BMI] threshold for determining that a driver must be referred for sleep testing).
they evaluate drivers who may be at risk of having OSA. Durand and Kales (2009) found that while members of the American College of Occupational and Environmental Medicine believed that screening for OSA was important, fewer than 50 percent used any specific criteria for such screening.
Until 2014, medical examiners could be any health care providers licensed by their state to perform physical examinations, including medical doctors; doctors of osteopathy; nurse practitioners; physician assistants; and in some states, chiropractors, dentists, or even physical therapists. The NRCME was fully implemented in 2014,9 and examiners on the registry are now required to be trained and certified in accordance with the NRCME Core Curriculum, which focused on the regulations, guidelines, and other official information from FMCSA available at that time.
With implementation of the NRCME, it was hoped that some consistency among medical examiners would be established, as all examiners were required to complete training that at least met the FMCSA Core Curriculum. While some training programs were limiting instruction to what was in the Medical Examiner Handbook, others were introducing additional resources, such as the MRB, MEP, or MCSAC recommendations, and still others were teaching (erroneously) that there were specific required criteria for screening drivers for OSA. The NRCME Medical Examiner Sample Training Handbook (National Registry of Certified Medical Examiners, 2012) noted that training programs could teach material beyond the Medical Examiner Handbook, provided they clearly highlighted that the material was not endorsed by FMCSA, and that examiners could use more current guidance than that issued by FMCSA in making certification determinations. FMCSA had indicated that, while the NRCME certification examination would include only information that had undergone public notice and comment, examiners should consider current best practice in making certification determinations, not only for OSA but also for other conditions for which official information from FMCSA was lacking, such as Parkinson’s disease or use of potentially impairing medications such as opioids.
FMCSA still has not provided specific guidance for medical examiners—this despite recommendations to the agency from the National Transportation Safety Board (NTSB) (2009); the expert recommendations of the FMCSA MEP, MRB, and MCSAC; and requests from the American
9 U.S. Department of Transportation Federal Motor Carrier Safety Administration. (2012). Final rule. National registry of certified medical examiners. Federal Register, 77(77), 24104-24135. Available: http://www.gpo.gov/fdsys/pkg/FR-2012-04-20/pdf/2012-9034.pdf [March 2016].
College of Occupational and Environmental Medicine (ACOEM).10 The absence of specific guidance to certified medical examiners on assessing CMV drivers for OSA presents challenges for employers who are relying on the examiners to make that determination but finding that inconsistent criteria are used, even within the same examiner group. There now exists a risk of grievances or legal action against employers or examiners that attempt to utilize current best practices and require diagnostic studies for some drivers. At the same time, lawsuits have been brought against employers and examiners when a crash has occurred; and the CMV driver subsequently has been found to have OSA but was not tested even though he or she would have been considered at high risk of the disorder based on one or more of the above recommendations. In January 2015,11 FMCSA issued a bulletin to medical examiners and training associations stating that examiners should use current best practices in determining which drivers should have objective testing and offering some considerations with respect to OSA, but noting that FMCSA has no specific requirements related to the disorder. Many examiners and employers have indicated that they will limit screening drivers for OSA until FMCSA issues specific guidance.
A 2014 survey (Hartenbaum, 2015) of examiners, both physicians and nonphysicians, both ACOEM-trained and not, who were listed on the NRCME demonstrated no consistency in examination outcomes for five scenarios in which current best practice would recommend that drivers have diagnostic testing for OSA. Selections included certify for 2 years, certify for 1 year and instruct driver to discuss risk of OSA with primary care physician, certify for 3 months and request documentation from primary care physician on risk of OSA, certify for 3 months and require sleep study, or not certify at all. The appropriate approach to screening CMV drivers for OSA remains contentious, and the absence of specific guidance affects drivers, examiners, employers, and third-party administrators.
Conclusion 4: It is apparent that medical examiners who certify commercial motor vehicle drivers are not consistent in understanding and applying current best practice to identify drivers who may be at risk of moderate to severe obstructive sleep apnea. Many examiners therefore
10 American College of Occupational and Environmental Medicine (ACOEM) letter to Congressmen Howard and Mica, June 28, 2010; and ACOEM letter to Administrator Ferro, July 24, 2013.
11 FMCSA Bulletin to Medical Examiners and Training Organizations Regarding Obstructive Sleep Apnea. Available: https://nationalregistry.fmcsa.dot.gov/NRPublicUI/documents/OSA%20Bulletin%20to%20MEs%20and%20Training%20Organizations-01122015.pdf [March 2016].
are inconsistent in making determinations as to when a driver should be referred for additional sleep testing.
The panel has no conclusions or suggestions for change regarding the diagnosis of non-OSA medical conditions that are associated with fatigue and can result in suspension of CMV driving privileges. Nonetheless, this section summarizes the evidence that is required for diagnosis of other medical conditions based on the FMCSA Medical Examiner Handbook.
Hypertension—elevated systolic or diastolic blood pressure—is a risk factor for cardiovascular disease, peripheral vascular disease, and chronic renal insufficiency. A person with a systolic blood pressure reading of greater than 140 or a diastolic reading of greater than 90 is regarded as having hypertension. CMV drivers are more likely to have hypertension than their peers in other professions (and there is some evidence that this gap is widening) (Thiese et al., 2015a, 2015b). The salient regulation in the Medical Examiner Handbook is as follows: “If a driver has hypertension and/or is being medicated for hypertension, he or she should be recertified more frequently. An individual diagnosed with Stage 1 hypertension (BP is 140/90-159/99) may be certified for one year. At recertification, an individual with BP equal to or less than 140/90 may be certified for one year; however if his or her BP is greater than 140/90 but less than 160/100, a one-time certificate for 3 months can be issued. . . . Once the driver has reduced his or her BP to equal to or less than 140/90, he or she may be recertified annually thereafter.”
About 8 percent of the population has diabetes, and one-third of cases may be undiagnosed. By contrast, the prevalence of diabetes in CMV drivers may be as high as 30 percent (Thiese et al., 2015a, 2015b), and evidence indicates that the incidence of diabetes in CMV drivers increased between 2005 and 2012. Factors that can affect blood glucose control are fatigue, lack of sleep, poor diet, and stress. Drivers diagnosed with diabetes mellitus who require insulin to control their condition are not eligible for certification because poorly controlled blood glucose can lead to fatigue, lethargy, and sluggishness, and complications can lead to acute hyperglycemia, which in turn can cause seizures, loss of consciousness, and impaired cognitive function. The medical examination relevant to
diabetes includes assessment of glycosuria, retinopathy, macular degeneration, peripheral neuropathy, coronary heart disease, cerebrovascular disease, autonomic neuropathy, and nephropathy.
Thiese and colleagues (2015a, 2015b) suggest that up to 5 percent of CMV drivers suffer from cardiovascular disease. The primary manifestations include acute myocardial infarction, angina pectoris, and congestive heart failure. Drivers that have cardiovascular disease, relative to those without, are more likely to experience sudden death or incapacitation. Since other conditions may exacerbate cardiovascular problems, the decision on certification of those with cardiovascular disease depends on a comprehensive medical assessment of overall health. However, if a driver is diagnosed with myocardial infarction, angina pectoris, coronary insufficiency, thrombosis, or any other cardiovascular disease known to be accompanied by syncope, dyspnea, collapse, or congestive cardiac failure, he or she is not to be certified for driving. The diagnosis includes evaluation for heart murmurs, extra heart sounds, arrhythmias, an enlarged heart, abnormal pulse, carotid or arterial bruits, or varicose veins. Details on cardiovascular problems and the increased risk for truck drivers can be found in FMCSA (2002) and the references included therein.
Long-haul CMV drivers face clear challenges to their health and wellness, including a sedentary lifestyle, limited access to healthy food, and sleep pressures. Based on a recent survey of long-haul truck drivers, Sieber and colleagues (2014) report that about 69 percent are obese (compared with 35.5% of the general population over age 20) (National Center for Health Statistics, 2015); 51 percent smoke (compared with 17.8% of adults older than 18) (National Center for Health Statistics, 2015); and few exercise regularly, which contributes to cardiac problems, diabetes, high blood pressure, and other morbidity. In addition, as discussed in Chapter 3, many commercial truck drivers get less than 6 hours of sleep at night (National Sleep Foundation, 2012), which is insufficient for most adults to maintain acceptable levels of alertness on the job and may eventually lead to adverse health consequences (Czeisler, 2015).
The panel emphasizes that these are broad generalizations that do not pertain to all CMV drivers. There are wide differences in drivers’ working conditions and lifestyles, work-rest schedules, and all related factors (e.g., sleep opportunities, availability of nutritious food, exercise facilities, work stressors, family life interactions). Truly comprehensive surveys in this
area have not been carried out, and given the diversity of CMV drivers, multiple surveys may be needed. In any case, much remains to be learned about fatigue, health behaviors, and their effects on CMV drivers.
Conclusion 5: Substantial data gaps limit understanding of factors that impact the health and wellness of commercial motor vehicle drivers. Closing these gaps would aid greatly in developing a better understanding of drivers’ current status and long-term prospects with respect to health and wellness.
That being said, the following description is generally correct. Long-haul commercial truck and bus drivers have unusual working conditions and lifestyles (see Chapter 2). Many contend with pervasive on-the-job stressors, such as the need to meet delivery schedules; constant traffic on the roadways; and monetary pressures given their income levels, which motivate them to work longer hours. Over-the-road truck driving may necessitate being away from home for weeks at a time, missing family members while away; facing extended periods of boredom while driving; sleeping in different settings every night, including use of sleeper berths; dining mainly in fast food restaurants; lacking adequate time or facilities for exercising; and remaining in sedentary work postures (sitting all day in the cab seat).12 CMV drivers’ use of tobacco products likely is greater than that among the general public (e.g., a National Institute for Occupational Safety and Health [NIOSH] survey [Sieber et al., 2014] found that 51% of the drivers surveyed smoked). As discussed in earlier chapters, drivers often must follow irregular work schedules that disrupt physiological bodily rhythms, affecting sleep and health, and they frequently experience degraded on-the-job alertness. While all CMV drivers may not have these same issues and many work more normal work schedules, they still have jobs that are primarily sedentary and pose other health risks.
There are some notable differences in driver regimens between commercial truck and bus drivers. Some bus drivers (e.g., those who drive tour buses) may work split schedules (tourists spend several hours on site before departing again for the next stop), and drivers handle passengers’ luggage for them. Some bus drivers work in two-person teams, but they have no sleeper berths; while en route, the second driver must sleep in
12 The association between whole-body vibration in truck driving and back problems was investigated in a NIOSH study (Blood et al., 2015). The study found that being exposed to seated whole-body vibration for extended periods is one of the leading risk factors for the development of low back disorders. Thus truck and bus drivers are at risk of developing back problems as they are regularly exposed to continuous whole-body vibration while driving heavy vehicles.
an awkward seated posture. By contrast, trucking team drivers may have comfortable sleeper berths for use by the second driver while the truck continues to move (Krueger and Van Hemel, 1997).
Partly as a result of their lifestyle, many long-haul truck drivers suffer from one or more medical conditions. As discussed above, they often have diabetes and suffer from cardiovascular problems; they may have undiagnosed sleep disorders such as OSA; they often experience musculoskeletal disorders (e.g., back pain) and injuries; and many are in generally poor health, which may adversely affect their driving performance and safety (see, e.g., Krueger, 2008; Krueger et al., 2007; Saltzman and Belzer, 2007). Moreover, many long-haul truck drivers lack access to adequate health care, especially while they are away from home. (Being constantly on the move makes it difficult to access regular health care when needed.) A NIOSH survey of U.S. long-haul truck drivers found that beyond lacking access to health care, 38.1 percent of drivers in the survey sample were not covered by health insurance or a health care plan. A small-scale cross-sectional study yielded similar findings (Apostolopoulos et al., 2010), with 33 percent of 316 participating truck drivers lacking health insurance. Not having access to adequate health care is especially common among CMV drivers, such as independent owner-operators, who do not work for large carriers. Large commercial carriers are more likely to arrange for health care and insurance programs for their employees. Many self-employed, owner-operator drivers who lack health insurance have been reported to be reluctant to obtain needed health care (Krueger, 2012; Saltzman and Belzer, 2007). Conceivably, with the implementation of the Affordable Care Act, some of these drivers will have improved access to health care.
Conclusion 6: Many commercial motor vehicle drivers work/live with occupational pressures that adversely affect health.
Given the impact of various aspects of the lifestyle of CMV driving, it is important to develop a better understanding of what aspects of that lifestyle are associated with negative health outcomes. There are many suggestions in the literature cited above and in previous chapters that CMV drivers’ insufficient sleep, or poor diet, or lack of exercise, or constant jostling, or stress contributes to their health problems. There are also suggestions that CMV driver’s compensation schemes contribute to their sleep insufficiency. Unfortunately, progress on isolating the factor(s) with the greatest impact on drivers’ health and understanding the extent to which behavioral changes result in improvements is greatly hampered by the lack of data in two important areas: (1) how CMV drivers live (especially how much sleep they get), and (2) how behavioral changes are related to improved health outcomes. As was mentioned in Chapter 5,
very few surveys of drivers have been carried out, and even in those surveys, reliable information on such important factors as the amount of sleep obtained and other aspects of the respondents’ lifestyle was not collected. Furthermore, the great majority of surveys that have been carried out have been cross-sectional. Absent longitudinal data collection, it is extremely difficult to understand how health outcomes change over time and how such changes occur in the absence or presence of various lifestyle modifications.
Conclusion 7: Insufficient data are available on the prevalence of sleep insufficiency, economic pressures, diet, and exercise habits for the population of commercial motor vehicle drivers.
Myriad types of health and wellness and fitness programs have been developed for drivers in the truck and bus industries, involving different levels of support and involvement by employers and participation by drivers. Driver health and wellness programs may be as simple as just offering health risk assessments (HRAs) and health and wellness tips and encouragement. But some employee (driver)-oriented programs include the following features: (1) conducting preemployment physicals, testing, diagnosis, and referrals for treatment; (2) employing health coaches who monitor and interact with drivers continuously while they are employed; (3) offering continuing education, hints, tips, and advice on healthy diet, weight loss, sleep and fatigue management, stress control, and lifestyle improvements; (4) conducting screening and treatment for selected sleep disorders, such as OSA (done primarily by a few large carriers); (5) offering participatory programs in health and wellness activities, such as physical fitness and exercise activities, health monitoring, and smoking cessation efforts; (6) offering motivational and incentive-based initiatives to promote employee participation in health and wellness programs, such as group games and competitions to foster weight loss and smoking cessation, providing lower-cost insurance premiums; and (7) encouraging participation in health and wellness programs by drivers’ family members.
Fatigue is clearly an important concern for highway safety. Many large fleets have taken proactive measures to improve their safety figures by implementing fatigue management programs in the workplace, often incorporating fatigue management into their ongoing employee health and wellness programs. On the other hand, independent owner-operators generally must address such issues as fatigue management and health and wellness on their own (Krueger, 2012). While that important
distinction exists, even fleets vary greatly in how fatigue is addressed and how health and wellness are managed. These approaches range from the minimum, which entails just complying with hours-of-service (HOS) regulations, to comprehensive programs for fatigue management and health and wellness that may include screening, training, treatment, and program evaluation.
One program, described to the panel by safety experts from Schneider National, showed that screening for OSA resulting in required use of PAP devices, if necessary, yielded positive benefits such as a substantial reduction in health care costs, a 30 percent reduction in accidents, and increased driver retention. Schneider National now prescreens all drivers for OSA, and its prescreening assessment was found to be 82 percent effective. (Some PAP devices document use, and this information can be used to terminate noncompliant drivers with OSA.)
Health and Wellness Programs of Large Carriers
While the panel did not undertake a systematic review of fatigue management or health and wellness programs instituted by large carriers, it was briefed on the experiences of three large carriers at its third meeting in September 2014. While the panel knows anecdotally that some small carriers have instituted health and wellness management programs, these appear to be few in number. This is to an extent understandable given the fixed costs of implementing such programs.
The panel heard about the employee health and wellness programs of Schneider National, J.B. Hunt, and Con-Way Motor Freight. Table 8-1 summarizes selected information from these presentations. These three carriers have integrated driver fatigue management into their health and wellness programs. Returns on investment in successful health and wellness programs include such benefits as improved employee morale and driver retention rates; enhanced corporate culture and reputation; decreased clinic visits and costs; improved insurance premium rates; and, importantly, decreased accidents and injuries, and therefore also improved safety records (Krueger, 2012).
Current Fatigue and Health and Wellness Programs in the Bus Industry
Hundreds of bus companies operate between 2 and 10 buses. Very little is known about the fatigue or health and wellness programs of these carriers. One example of a fatigue management program of a large interstate bus company was brought to the panel’s attention by the chair of the Bus Industry Safety Council for the American Bus Association, Michael
TABLE 8-1 Health and Wellness Programs of Three Large Carriers as of September 2014
|Component||Schneider National||J.B. Hunt||Con-Way Motor Freight|
|Pre- and Postjob Screening||Prework physical screen||Electronic physicals and customized tests|
|Training||Injury prevention training||Job safety analysis||Safety coaching, injury prevention coaching|
|Health and Wellness||
||Better Health for Life Program, J.B. Hunt Health Moves Program||On-site safety and health coaching|
|Sleep Apnea||Screening and treatment program||Sleep apnea clinical trial||Sleep study|
McDonal. In his presentation to the panel, he stated that Greyhound, a large bus company, has a fatigue management initiative based on input received from focus groups comprising drivers, operations managers, and safety directors throughout the industry. On the basis of input from focus groups, Greyhound developed countermeasures to address driver stress and fatigue. Data were collected on the effectiveness of these measures
from a small set of drivers during actual night runs. Based on these data, extra board operations were modified.13
Fatigue Outreach and Health and Wellness Initiatives of FMSCA
Since the mid-1990s, FMCSA has encouraged carriers to engage in employer-sponsored driver fatigue management programs. To this end, the agency has conducted extensive education and outreach; held forums on the topics; and carried out extensive research on driver fatigue and performance in conjunction with cooperative, enlightened truck and bus carriers. In terms of continuously addressing driver fatigue management, FMCSA developed and sponsored (with industry) the Mastering Alertness and Managing Driver Fatigue train-the-trainer 4-hour course, which was offered to more than 4,500 trucking safety and risk managers from 1996 until 2006. FMCSA also arranged to develop (with industry) an employee health, wellness, and fitness program entitled “Gettin’-InGear,” a train-the-trainer program offered to more than 2,500 trucking safety and risk managers from 2001 to 2006.
The North American Fatigue Management Program (NAFMP), sponsored by FMCSA, Transport Canada, and others, has been available on its own dedicated website since summer 2013. This extensive set of more than 800 slides is offered in 10 training modules aimed at employers, managers, drivers, shippers, and receivers. The 10 modules are (1) introduction and overview, (2) safety culture and management practices, (3) driver education, (4) family education, (5) train the trainer, (6) truck driver safety and compliance: the role of shippers and receivers, (7) sleep disorders management for motor carriers, (8) driver sleep disorders management, (9) driver scheduling and tools, and (10) fatigue monitoring and management technologies.
NAFMP serves as an information source for the entire ground shipping industry. It offers numerous health and wellness lessons; fitness principles; and coverage of additional selected topics, especially those related to sleep hygiene, including sleep disorders such as OSA. For example, the program covers the effects of being continuously jostled, consuming a bad diet, not exercising, poor weight management, high blood pressure, using various medications, using alcohol, using tobacco, disruption of circadian rhythms, and resultant conditions such as diabetes.
As noted by Terri Hallquist of FMCSA in her presentation at the panel’s third meeting, there is currently no effort under way to evaluate
13 For details on Greyhound’s Alertness Management Program, see http://onlinepubs.trb.org/onlinepubs/conferences/2011/FatigueInTransit/Presentations/Al%20Smith.pdf [March 2016].
who visits the NAFMP website or whether those who do visit are engaging in any behavior modification, such as sleeping longer.14 This lack of evaluation to date is likely the result of the program’s recent implementation. As discussed in Chapter 11, some evaluation of the program is feasible using web analytics. Given the attention paid to fatigue and health and wellness management by the large carriers, one key concern is whether NAFMP is adequate to educate and motivate behavior change among drivers for many midsize carriers that lack such programs or for small carriers with only a handful of trucks and drivers, or among the hundreds of thousands of independent owner-operator drivers nationwide.
Conclusion 8: Insufficient information exists on (1) how the variety of fatigue management and health and wellness management programs available have been designed, (2) whether drivers/employers actually adhere to these programs, and (3) whether these programs are effective in achieving their goals.
14 Note that FMCSA recently also instituted an online resource to help CMV drivers understand how a medication might impact their ability to drive safety. See http://www.fmcsa.dot.gov/medical/driver-medical-requirements/medication-issues [March 2016].
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