Many Americans assume that the health care they receive is based on strong medical evidence of intervention and treatment effectiveness. However, as suggested by regional analyses, recommended care is often not delivered and insufficient evidence often leads to wide practice variations with little to no health benefit to patients (Fisher et al., 2003b; McGlynn et al., 2003). In addition to negatively impacting health outcomes, practice inconsistencies have dramatic effects on the overall costs of health care—costs which represent the most pressing fiscal challenge to the nation. Papers in this chapter examine the drivers of practice variations and healthcare costs and suggest the potential for an improved evidence base to improve the efficiency and effectiveness of healthcare services.
The majority of U.S. healthcare expenditures today are related to the care and treatment of chronic conditions such as heart disease, diabetes, and asthma, which affect almost half of the U.S. population. Evidence for effective strategies for care delivery in these areas is limited, resulting in care that is fragmented, uncoordinated, and characterized by unnecessary duplication of services. In Elliott S. Fisher’s paper, small-area analyses reveal that differences in care delivery explain almost all of the geographic variations in spending across the United States, and that higher-spending regions of the country perform worse in measures of technical quality than regions that spend less money. When there is strong medical evidence, physicians tend to agree on courses of treatment across regions of different spending levels. Building an evidence base for areas in which physicians currently
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2
The Need for Better Medical Evidence
INTRODUCTION
Many Americans assume that the health care they receive is based on
strong medical evidence of intervention and treatment effectiveness. How-
ever, as suggested by regional analyses, recommended care is often not de-
livered and insufficient evidence often leads to wide practice variations with
little to no health benefit to patients (Fisher et al., 2003b; McGlynn et al.,
2003). In addition to negatively impacting health outcomes, practice incon-
sistencies have dramatic effects on the overall costs of health care—costs
which represent the most pressing fiscal challenge to the nation. Papers in
this chapter examine the drivers of practice variations and healthcare costs
and suggest the potential for an improved evidence base to improve the
efficiency and effectiveness of healthcare services.
The majority of U.S. healthcare expenditures today are related to the
care and treatment of chronic conditions such as heart disease, diabetes,
and asthma, which affect almost half of the U.S. population. Evidence for
effective strategies for care delivery in these areas is limited, resulting in
care that is fragmented, uncoordinated, and characterized by unnecessary
duplication of services. In Elliott S. Fisher’s paper, small-area analyses reveal
that differences in care delivery explain almost all of the geographic varia-
tions in spending across the United States, and that higher-spending regions
of the country perform worse in measures of technical quality than regions
that spend less money. When there is strong medical evidence, physicians
tend to agree on courses of treatment across regions of different spending
levels. Building an evidence base for areas in which physicians currently
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0 EVIDENCE-BASED MEDICINE
use their own discretion, such as the comparative effectiveness of various
treatment options, or decisions about how often to see a patient with well-
controlled hypertension and when to order certain medical tests, could
greatly improve the quality of care and reduce costs. In fact, if all regions
adopted the practice patterns of the most conservatively spending regions
of the country, health outcomes could be significantly improved and U.S.
healthcare spending could decline by as much as 30 percent.
Peter R. Orszag’s presentation illustrates the serious consequences that
excessive healthcare spending poses to the nation’s economic well-being. If
spending growth trends continue as they have over the past four decades, by
2050 Medicare and Medicaid spending will account for 20 percent of the
total U.S. economy. Although often ascribed to effects of an aging popula-
tion, lower fertility rates, and longer life expectancies, this long-term fiscal
challenge is driven almost entirely by excessive healthcare costs—or costs
per beneficiary. Slowing overall healthcare cost growth without limiting
access will require changes that impact the overall healthcare system and
providing better evidence to inform decision making will be an important
first step. Comparative effectiveness research that draws upon the emerging
electronic health record and clinical registry data resources may be the only
cost-effective and feasible mechanism for bringing about the evidence-base
expansion needed. Real gains in improving the quality of health care and
reducing costs will come when the evidence of medical effectiveness is tied
to incentive payments for healthcare providers. A combination of increased
cost sharing on the consumer side combined with changes in the incentive
system for providers informed by best evidence offers an important oppor-
tunity to substantially reduce healthcare costs and improve quality.
HEALTH CARE AND THE EVIDENCE BASE
Elliott S. Fisher, Dartmouth Medical School
The U.S. healthcare system faces serious challenges and the Institute
of Medicine (IOM) has played a critical role in calling for fundamental
transformation of the delivery system to achieve the vision of a patient-
centered, high-quality, equitable, and effective delivery system (IOM, 2001,
2006). There is also a growing recognition that our current delivery system
is failing to deliver on the promise of improved health offered by advances
in biomedical knowledge, and the future pace of change may widen this
gap substantially.
The IOM Roundtable on Evidence-Based Medicine was established “to
help transform the way evidence on clinical effectiveness is generated and
used to improve health and health care” (IOM, 2007a). The key notions are
to provide better evidence about the risks and benefits of interventions and
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THE NEED FOR BETTER MEDICAL EVIDENCE
to support better application of that knowledge to clinical practice. Several
recent reports highlight the growing consensus on the need for expanded
support for comparative effectiveness research that provides better informa-
tion about the risks and benefits of specific treatments (IOM, 2007b).
This paper draws on the traditions of small-area analysis to under-
score the scope of the challenge faced in bringing evidence to bear on
current practice and to point to the opportunity for improving both the
costs and the quality of care by ensuring a broad definition of the need for
evidence.
Categories of Care: Biologically Targeted Interventions
Versus Care Management Strategies
As we consider the relationship between evidence and clinical practice,
it is worth considering two broad categories of interventions: discrete, bio-
logically targeted interventions and care delivery strategies.
Biologically targeted interventions are focused on a specific anatomic
problem or disease process. Examples include the decision about whether to
adopt a specific screening test for cancer or whether to treat a patient with
prostate cancer with surgery or radiation therapy. Such interventions can be
well specified not only in terms of the underlying anatomic or physiologic
problem to be addressed, but also in terms of the expected intermediate and
long-term outcomes and how these vary across clinical subgroups. Many
of the dramatic improvements in health outcomes achieved over the past
decades are a result of the advances in biomedical knowledge and the devel-
opment of such biologically targeted interventions. These are the traditional
focus of technology assessment, clinical guidelines, and a narrow definition
of “evidence-based practice.”
A second category of “decisions,” which I refer to as care delivery strate-
gies, is rarely considered explicitly in the day-to-day practice of clinical medi-
cine. This category refers not to what care is provided (what drug, what device,
what surgical procedure) or to whom (which patients should be offered the
intervention), but to how a specific biologically targeted therapy is delivered:
who should provide the care (patients themselves, advanced practice nurses,
primary care physicians, or specialists); where care should be delivered (home,
outpatient facility, or hospital); and how intensively patients should be moni-
tored and reevaluated. Questions about care delivery also encompass system-
and policy-level issues, such as how care should be organized, what kinds of
resources should be deployed, how care should be paid for and financed, and
how to improve the quality of care.
There are three reasons to distinguish these two categories of decisions.
First, the effectiveness of many (if not most) discrete biologically targeted
interventions can depend critically on how care is provided: risk-adjusted
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2 EVIDENCE-BASED MEDICINE
surgical mortality rates, for example, vary severalfold across hospitals
(Birkmeyer et al., 2002; O’Connor et al., 1991). Second, as discussed below,
regional and provider-specific differences in costs are largely due to differ-
ences in the intensity of care delivery: addressing the rapidly rising costs of
care will require much better evidence about how to organize and deliver
care effectively and efficiently. Finally, I argue that the infrastructure re-
quired to provide better evidence on discrete, biologically targeted interven-
tions is fundamentally the same as the infrastructure required to improve
care delivery. As we build our capacity to improve evidence, we should be
careful to address the need for better evidence along both dimensions.
Current Practice and the Evidence Base:
Biologically Targeted Interventions
The recent IOM workshop on evidence-based medicine highlighted
the many limitations of the current evidence base, focusing primarily on
the challenges surrounding biologically targeted therapies (IOM, 2007a).
Highlights include the lack of any evidence on the efficacy or effectiveness
of many interventions, the difficulty of extrapolating from trials carried
out on selected populations to those with multiple chronic conditions, and
the growing recognition that the benefits of interventions vary according to
the underlying risk of the population: trials that show benefit for the aver-
age patient may not reveal that many lower-risk patients may be harmed
by receiving the procedure while those at greater risk receive substantial
benefits. The growing recognition of the importance of comparative effec-
tiveness research can be attributed to the increasing attention focused on
these issues.
The relative magnitude of the uncertainty surrounding the use of se-
lected, discrete, biologically targeted therapies can be illustrated by the
regional variations in rates of these services among the Medicare population
(Figure 2-1). We have found it useful to distinguish effective care (treat-
ments where the evidence of benefit is strong and no trade-offs among
benefits and harms are involved) from preference-sensitive care (treatments
where patients’ values about the different outcomes may vary1) (Wennberg
et al., 2002). An example of the former would be hospitalizations for hip
fracture: the diagnosis is straightforward and the therapy (inpatient surgi-
cal repair of the fracture) is required. Variations in utilization rates are due
entirely to underlying variations in the incidence of the disease. Examples
1 The importance of ensuring that care is aligned with patients’ well-informed preferences
applies not only to discrete, biologically targeted interventions, but also to care delivery
strategies.
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THE NEED FOR BETTER MEDICAL EVIDENCE
5.0
St andardized ratio ( log scale)
1.0
0.2
Hip f ractu re PSA Ca rd iac PCI Radica l
discha rges catheter izat ion prostatectomy
Coefficient of va riat ion 12.7 25.2 28.0 34.0 38.5
Interqua rt ile ratio 1.19 1.40 1.44 1.43 1.71
Extremal ratio 3.95 4.33 4.20 11.50 8.69
FIGURE 2-1 Variation in utilization rates of specific, biologically targeted
interventions.
NOTE: Each dot represents the ratio of the rate of the specified intervention in one
of the 306 U.S. Hospital Referral Regions to the U.S. average for that intervention
2-1.eps
(log scale). All rates are calculated on an annual basis for fee-for-service Medicare
enrollees age 65 and over. PSA refers to prostate-specific antigen testing at least once
during the year. PCI refers to percutaneous coronary interventions. Data are from
the Dartmouth Atlas of Health Care.
of the latter would include screening for prostate cancer (where patient
attitudes toward the risks of treatment must be weighed against the still
unproven benefits of screening) or percutaneous coronary interventions
for stable angina (where the modest benefit in terms of angina relief must
be weighed against the lifelong need for anti-platelet therapy among other
risks). When we look at common biologically targeted interventions—both
diagnostic and therapeutic—we see dramatic variability across the United
States. Addressing these variations will require not only better informa-
tion about risks and benefits (comparative effectiveness research), but also
ensuring that treatment decisions reflect the well-informed judgments of
patients rather than the opinions of providers (O’Connor et al., 2007;
Wennberg et al., 2007).
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EVIDENCE-BASED MEDICINE
Current Practice and the Evidence Base: Care Delivery Strategies
There are also marked differences across regions in the way care is
delivered (Figure 2-2). Although virtually all Medicare beneficiaries have
access to care (defined as at least one physician visit during the year) and
there is thus little regional variation in the age-, sex-, or race-adjusted
rate of at least one physician visit, we see marked variability in the use of
other care delivery strategies. Because variation in use of these services is
associated with the local capacity of the delivery system (how many physi-
cians, how many hospital beds), we have long referred to these services as
“supply-sensitive.”
One of the fundamental reasons for distinguishing care delivery strat-
egies from the use of biologically targeted interventions is their distinct
5.0
St andardized ratio ( log scale)
1.0
0.2
At least Primar y Medica l 10 or more Medica l Inpatient ICU days
one visit ca re visits specia list MDs ( L6M) discha rges days (L6M)
visits
Coefficient of va riat ion 5.1 14.2 33.6 35.9 18.7 20.5 41.7
Interqua rt ile ratio 1.05 1.21 1.56 1.64 1.30 1.36 1.75
Extremal ratio 1.48 2.80 5.61 6.12 3.37 2.88 11.65
FIGURE 2-2 Variation in utilization rates of care delivery strategies.
NOTE: Each dot represents the ratio of the rate of the specified service or strategy
2-2.eps
in one of the 306 U.S. Hospital Referral Regions to the U.S. average for that service
(log scale). Visits, medical discharges, and inpatient days are calculated on an annual
basis for fee-for-service Medicare enrollees age 65 and over. Data for the proportion
of enrollees seeing 10 or more physicians and for intensive care unit (ICU) days are
for Medicare enrollees with chronic illness who are in their last 6 months of life
(L6M). Data are from the Dartmouth Atlas of Health Care.
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THE NEED FOR BETTER MEDICAL EVIDENCE
relationship to variations in spending. Figure 2-3 displays the relationship
between spending and the utilization rates of specific types of services
across U.S. regions. Each dot represents the ratio of the utilization rates of
the specific service in regions that fall in the highest quintile to the utiliza-
tion rate in the lowest-spending quintile of regional per capita Medicare
spending. To control for potential differences in the underlying health
status of populations across regions, these analyses are based on long-term
follow-up of patients initially hospitalized with hip fracture, colon cancer,
or acute myocardial infarction (Fisher et al., 2003a). Higher spending is not
associated with greater use of biologically targeted interventions: whether
these are treatments that all patients should receive (effective care) or in-
Utilization ratio of highest to lowest quintile
0.5 1.00 1.5 2.0 2.5 3.0
Discrete : strong evidence
Reperfusion in 12 hours ( Heart attack)
Aspirin at admission ( Heart attack)
Mammogram, Women 65 -69
Pap Smear, Women 65 +
Pneumococcal Immunization
Discrete : major discretionary procedures
Total Hip Replacement
Total Knee Replacement
Back Surger y
CABG following hear t attack
Care management: who / how often / where
Total Inpatient Days
Inpatient Days in ICU or CCU
Evaluation and Management (visits)
Imaging
Diagnostic Tests
0.5 1.00 1.5 2.0 2.5 3.0
Use Rate Lower in High-Spending Regions Use Rate Higher in High-Spending Regions
FIGURE 2-3 Ratio of utilization rates for selected specific services among cohorts
of Medicare beneficiaries in high- 2-3 new.eps
versus low-spending regions.
NOTE: High- and low-spending regions were defined as the U.S. Hospital Referral
Regions in the highest and lowest quintiles of per capita Medicare spending. Data
for mammograms, Pap smears, and pneumococcal immunizations were ascertained
from a representative sample of the Medicare population. Data for all other utiliza-
tion rates reflect either acute care for patients with heart attacks (reperfusion and
aspirin administration) or the weighted average of utilization rate ratios during
one year follow-up after initial hospitalization for acute myocardial infarction,
hip fracture, or colorectal cancer. All data are from Fisher and colleagues (Baicker
et al., 2007).
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EVIDENCE-BASED MEDICINE
terventions where patients’ judgments about how they value the risks and
benefits should determine the treatment choice (preference-sensitive care).
Higher spending, however, is largely due to differences in care delivery: how
frequently patients are seen (evaluation and management services), how
much time they spend in the hospital, and the intensity with which they are
monitored (diagnostic tests and imaging).
Spending, the Intensity of Care Delivery, and Health Outcomes
The critical question underlying the variations in practice and spending
is their relationship to health outcomes. Over the past 10 years, a number
of studies have explored the relationship between higher spending and the
quality and outcomes of care (Table 2-1).
Patients’ Experiences and Outcomes
Whether the study was carried out at the state level (Baicker and
Chandra, 2004), across hospital referral regions (Fisher et al., 2003a), or
across the major academic medical centers within the United States (Fisher
et al., 2004), a consistent pattern is found: the quality of care as reflected
in process measures of care is worse when spending—and the intensity of
care delivery—is greater. Among patients hospitalized with hip fractures,
colon cancer, and acute myocardial infarction who were followed for up
to five years, mortality rates in higher-spending regions and hospitals were
no better or slightly worse than in lower-spending delivery systems (Fisher
et al., 2003a). In regions where spending growth was greatest, survival
following myocardial infarction improved more slowly than in regions
where spending growth was slower (Skinner et al., 2006). Finally, Medicare
beneficiaries’ overall satisfaction with care was no better in higher-spending
regions and their perceptions of the accessibility of care were somewhat
worse (Fisher et al., 2003a).
Physician Attributes, Practice Settings, and Perceptions of Care
On a per capita basis, the highest-spending quintile of hospital refer-
ral regions have 65 percent more medical specialists per capita, 75 percent
more general internists, and 25 percent fewer family practitioners than the
lowest-spending quintile. A substantially higher proportion of physicians
are foreign medical graduates, fewer are board certified, and they are much
more likely to practice in small groups than physicians in lower-spend-
ing regions (Sirovich et al., 2006). When surveyed, physicians in higher-
spending regions are more likely to report that the continuity of care with
their patients is inadequate to support high-quality care and that the quality
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THE NEED FOR BETTER MEDICAL EVIDENCE
TABLE 2-1 Relationship Between Regional Differences in Spending and
the Content, Quality, and Outcomes of Care
Higher-Spending Regions Compared to Lower-Spending Onesa
Healthcare • Per capita supply of hospital beds 32% higher (Fisher et al., 2003a)
resources • Per capita supply of physicians 31% higher overall: 65% more
medical specialists, 75% more general internists, 29% more surgeons,
and 26% fewer family practitioners (Fisher et al., 2003a)
Content and • Adherence to process-based measures of quality lower (quality worse)
quality of care • Little difference in rates of major elective surgery (Fisher et al., 2003a;
Wennberg et al., 2002)
• More hospital stays, physician visits, specialist referrals, imaging, and
minor tests and procedures (Fisher et al., 2003a)
Health • Mortality up to 5 years slightly higher following acute myocardial
outcomes infarction, hip fracture, and colorectal cancer diagnosis (Fisher et al.,
2003a)
• No difference in functional status (Fisher et al., 2003a)
Physician • More likely to report poor communication among physicians (Sirovich
perceptions of et al., 2006)
quality • More likely to report inadequate continuity of patient care (Sirovich
et al., 2006)
• Greater difficulty obtaining inpatient admissions or high-quality
specialist referrals (Sirovich et al., 2006)
Patient-reported • Worse access to care and greater waiting times (Fisher et al., 2003a)
quality of care • No difference in patient-reported satisfaction with care (Fisher et al.,
2003a)
Trends over • Although all U.S. regions experienced improvements in acute
time myocardial infarction survival between 1986 and 2002, regions with
greater growth in spending had smaller gains in survival than those
with lower growth in spending (Skinner et al., 2006)
aHigh- and low-spending regions were defined as the U.S. Hospital Referral Regions in the
highest and lowest quintiles of per capita Medicare spending as in Fisher et al. (2003a).
of communication is insufficient to support high-quality care. In spite of the
substantially greater per capita supply of both beds and specialists, physi-
cians in higher-spending regions are more likely to perceive scarcity: they
are more likely to report that it is difficult to get a patient into the hospital
and that it is hard to obtain adequate medical specialist referrals.
These findings are consistent with the hypothesis that the lower-
spending regions represent a reasonable benchmark of efficiency. In fact, if
all U.S. regions could safely adopt the organizational structures and prac-
tice patterns of the lowest-spending regions of the United States, Medicare
spending would decline by about 30 percent (Fisher et al., 2003a; Wennberg
et al., 2002). While it may not be realistic to reduce spending by that
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EVIDENCE-BASED MEDICINE
amount, the magnitude of the differences in practice and the fact that the
differences in spending are largely due to differences in care delivery point
to an important opportunity: improving efficiency will require attention
not only to the comparative effectiveness of biologically targeted interven-
tions, but also to addressing the underlying causes of the differences in care
delivery across regions and systems.
Underlying Causes of the Differences in Care Delivery:
Evidence and Theory
The Evidence
A number of studies have explored the underlying causes of the re-
gional differences in spending and the intensity of care delivery. Patients’
preferences for care vary slightly across regions, but not enough to explain
the magnitude of spending differences seen. For example, Medicare ben-
eficiaries in high-spending regions are no more likely to prefer aggressive
end-of-life care than those in low-spending regions (Barnato et al., 2007;
Pritchard et al., 1998). Differences in the malpractice environment are asso-
ciated with differences in both practice and spending, but explain less than
10 percent of state-level differences in spending and have a comparably
small impact on differences in the growth in spending across states (Baicker
et al., 2007; Kessler and McClellan, 1996). The role of capacity is clearly
important, but the hospital bed supply and physician supply combined
explain less than 50 percent of the difference in spending across regions
(Fisher et al., 2004).
The most recent studies have focused on the use of clinical vignettes to
explore how physicians’ judgments vary across regions of differing spend-
ing levels. These studies have found that physicians in higher-spending re-
gions were no more likely to intervene in cases where evidence was strong
(such as chest pain with an abnormal stress test), but were much more likely
to recommend discretionary treatments (such as more frequent visits, refer-
ral to a specialist, or use of imaging services) than those in low-spending
regions (Sirovich et al., 2005).
A Likely Diagnosis: Capacity, Payment, and Clinical Culture
These findings suggest a likely explanation for the dramatic differ-
ences in spending across regions and the paradoxical finding that higher
spending seems to lead to worse quality and worse outcomes. Current
clinical evidence is an important, but limited, influence on clinical decision
making. Most physicians practice within a local organizational context
and policy environment that profoundly influences their decision making,
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THE NEED FOR BETTER MEDICAL EVIDENCE
especially in discretionary clinical settings. Hospitals and physicians each
face incentives that will in general reward expansion of capacity (especially
for highly reimbursed services) and recruitment of additional procedure-
oriented specialists. When there are more physicians relative to the size of
the population they serve, physicians will see their patients more frequently.
When there are more specialists or hospital beds available, primary care
physicians and others will learn to rely upon those specialists and use those
beds. (It is more efficient from the primary care physician’s perspective to
refer a difficult problem to a specialist or to admit a patient to the hospital
than to try to manage the patient in the context of an office visit for which
payments have become relatively constrained.)
The consequence is that what—given the state of current evidence—are
“reasonable” individual clinical and policy decisions lead in aggregate to
higher utilization rates, greater costs, and inadvertently, worse quality and
worse outcomes. The key element of this theory is that because so many
clinical decisions are in the “gray areas” (how often to see a patient, when
to refer to a specialist, when to admit to the hospital), any expansion of
capacity will result in a subtle shift in clinical judgment toward greater
intensity.
Implications for Evidence Development
These findings and their likely explanation point to the need for much
better evidence. We need evidence about the risks and benefits of discrete,
biologically targeted interventions and how these risks and benefits vary
across different subgroups of the population, especially those often excluded
from current randomized trials (IOM, 2007b), but we also need much better
evidence about care delivery. No matter how good our clinical evidence about
specific interventions becomes, many—if not most—clinical decisions will
still require judgment. Also, because there will always be gray areas, we
will need evidence that can guide clinicians, administrators, and policy
makers when they are making decisions about care delivery.
Although the need for evidence may appear overwhelming, an im-
portant opportunity lies in recognizing that the information systems and
analytic approaches required to improve the evidence base for biologically
targeted interventions and for improving care delivery are fundamentally
the same (Table 2-2). In the ideal world of improved information systems
and electronic records that might allow relatively routine assessment of
both short- and long-term health outcomes and effective follow-up of pa-
tients, the capacity to evaluate both care delivery and biologically targeted
interventions would be critical, at least in part because lack of information
about the local context (delivery system attributes) would sharply limit our
ability to properly interpret studies of biologically targeted interventions.
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0 EVIDENCE-BASED MEDICINE
TABLE 2-2 Relationship Between the Information and Approaches
Required to Improve the Evidence Base Around Biologically Targeted
Interventions and Care Delivery
Discrete, Biologically
Targeted Interventions Approaches to Care Delivery
Example of research How effective are How should primary care
question endovascular carotid artery offices be organized to provide
stents in the prevention of care to patients with heart
stroke? failure?
Outcomes of interest Survival, functional status, Survival, functional status,
quality of life, total costs quality of life, total costs
Comparison of interest Carotid stent vs. medical Offices meeting criteria for
therapy “medical home” vs. other
primary care offices
Important patient-level Age, sex, race, severity Age, sex, race, severity
factors required for either of illness, comorbidities, of illness, comorbidities,
adjustment or stratification socioeconomic status socioeconomic status
Contextual factors Attributes of care delivery Attributes of care delivery
required for adjustment or system system
stratification
Applicable methods Randomized trials Randomized trials
and/or population-based and/or population-based
observational studies observational studies
Key notion Compare biologically Compare care delivery
targeted interventions, strategies, while accounting
while accounting for for patient and contextual
patient and contextual factors
factors
Moving Forward: A Challenge to Academic Medicine
The critical importance of healthcare spending to the future financial
health of the U.S. government and the economy in general has received
growing attention (Orszag and Ellis, 2007). Our capacity to provide af-
fordable healthcare coverage to the U.S. population and our ability to pay
for the new biologically targeted interventions that are under development
will clearly depend not only on the costs of the interventions but also on
the costs of delivering those interventions. Academic medicine—and the
federal agencies that provide research support—have largely focused on
improving our understanding of disease biology, while ignoring the need
to understand and address the dramatic variations in care delivery among
academic medical centers (Wennberg et al., 1987).
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THE NEED FOR BETTER MEDICAL EVIDENCE
Table 2-3 points to the magnitude of the opportunity—and the
challenge—for academic medicine. The upper portion of the table focuses
on the degree to which each of these five members of the U.S. News and
World Report’s “Honor Roll” of academic medical centers is able to deliver
proven clinical interventions to eligible patients during an acute inpatient
stay. The lower portion of the table highlights the differences in spending
and overall intensity of care. The specific data focus on care provided in the
last six months of life, but these patterns of practice are highly predictive
of how these institutions treat other seriously ill patients. All five provide
TABLE 2-3 Performance of Selected Major Academic Medical Centers
on Measures of Adherence to Biologically Targeted Treatments and the
Intensity of Care Delivery
UCLA Johns Massachusetts Cleveland Mayo Clinic
Medical Hopkins General Clinic (St. Mary’s
Center Hospital Hospital Foundation Hospital)
Provision of
discrete, biologically
targeted evidence-
based interventions
Composite quality 81.5 84.3 85.9 89.2 90.4
score on measures
of inpatient
technical quality
Spending and care
delivery for patients
with serious chronic
illness during last
months of life
Medicare spending 50,522 43,363 40,181 28,077 26,330
Physician visits 52.1 29.8 42.2 32.2 23.9
Hospital days 19.2 17.1 17.7 14.6 12.9
Intensive care days 11.4 4.3 2.8 3.5 3.9
% admitted to 26.1 31.5 19.6 34.2 25.5
hospice
% seeing 10 or 57.7 44.3 54.6 46.8 43.0
more physicians
NOTES: Hospitals were selected for inclusion because they were ranked as the top five aca-
demic medical centers on the U.S. News and World Report’s 2007 “Honor Roll.” Utilization
data are for 1999-2003. Composite quality score was calculated from CMS data for 2005,
which are from the Dartmouth Atlas of Health Care.
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2 EVIDENCE-BASED MEDICINE
high-quality inpatient care. The differences in care delivery, however, are
substantial: patients at the University of California, Los Angeles, have twice
as many visits, spend about 50 percent more time in the hospital, and cost
about twice as much as those treated at the Mayo Clinic in Rochester, Min-
nesota, or the Cleveland Clinic.
If all U.S. delivery systems could achieve the apparent efficiency of a
Mayo or a Cleveland Clinic, the resources available to expand coverage to
the uninsured or to provide interventions of proven benefit to those who
are not be able to afford them would be substantial. Failure to address this
challenge would call into question not only the scientific integrity of the
enterprise (Are we really committed to asking important questions?), but
also our moral authority as healthcare providers (How can we continue to
ignore obvious opportunities to improve quality and the future affordability
of care?).
Academic medicine has the opportunity to lead the development of a
learning healthcare system. Such an effort should include a focus not only
on the science of disease biology and improving the evidence to support
the use of biologically targeted interventions, but also on the sciences of
clinical practice and the evidence to support improvements in care delivery
(Wennberg et al., 2007).
THE HIGH PRICE OF THE LACK OF EVIDENCE
Peter R. Orszag, Congressional Budget Office
The nation’s long-term fiscal challenge has largely been misdiagnosed in
popular descriptions. It typically is described as being driven mostly by the
aging of baby boomers, with lower fertility rates and longer life expectancy
causing most of the long-term budget problem. In fact, most of that long-
term problem is driven by excess healthcare cost growth—that is, the rate
at which healthcare costs grow compared to income per capita. In other
words, it is the rising cost per beneficiary, rather than the number of benefi-
ciaries, that explains the bulk of the nation’s long-term fiscal problem.
You can see this phenomenon arising even over the next decade: Fig-
ure 2-4 shows the Congressional Budget Office’s (CBO’s) projections for
spending on Social Security, Medicare, and Medicaid through 2017. As
the figure shows, Social Security rises by about 0.5 percentage points of
gross domestic product (GDP), from 4.2 percent of GDP to 4.8 percent
over that period. Medicare and the federal share of Medicaid rises from
4.6 percent of GDP to 5.9 percent of GDP—an increase of 1.3 percentage
points of GDP, or roughly twice as much as Social Security even over the
next decade.
If you look over longer periods of time, the basic point is accentuated.
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THE NEED FOR BETTER MEDICAL EVIDENCE
7
Medicaid
Medicare 5.9
6
Social
Security
5 4.8
1.9
4.6
4. 2
4 1.4
3
4.8
4. 2
2 4.0
3.2
1
0
2007 2017
FIGURE 2-4 Spending on Medicare and Medicaid and on Social Security as a per-
centage of GDP, 2007 and 2017.
2-4.eps
Figure 2-5 shows a simple extrapolation in which Medicare and Medicaid
costs continue to grow at the same rate over the next four decades as they
did over the past four. (Even with no change in federal policy, there are
reasons to believe that this simple extrapolation may overstate future cost
growth in Medicare and Medicaid. CBO has recently released a long-term
health outlook that presents a more sophisticated approach to projecting
Medicare and Medicaid costs under current law, but a straight historical
extrapolation is shown here for simplicity.) Under that scenario, Medicare
and Medicaid would rise from 4.6 percent of the economy today to 20
percent of the economy by 2050; 20 percent of GDP is the entire size of
the federal government today.
The most interesting part of Figure 2-5 is the bottom line, which iso-
lates the pure effect of demographics on those two programs. The only
reason that the bottom line is rising is that the population is getting older
and there are more beneficiaries on the two public programs. The increase
between today and 2050 in that bottom dotted line shows that aging does
indeed affect the federal government’s fiscal position. Yet that increase is
much smaller than the difference in 2050 between the bottom line and the
top line. In other words, the rate at which healthcare costs grow—whether
they continue to grow at 2.5 percentage points per year faster than per
capita income, or 1 percentage point, or 0.5 percentage point, is to a
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EVIDENCE-BASED MEDICINE
25
Actual Projection
Differential of :
2.5 Percentage Points
Percent of Gross Domestic Product
20
1 Percentage Point
Zero
15
10
5
0
19 66 1972 1978 1984 1990 1996 20 02 20 08 2014 2020 2026 2032 2038 20 44 20 50
FIGURE 2-5 Total federal spending for Medicare s Medicaid under assumptions
2-5 new.epand
about the health cost growth differential.
SOURCE: Congressional Budget Office, 2007.
first approximation the central long-time fiscal challenge facing the United
States.
It is common to say that the sooner we act the better off we are, and
just to calibrate that, Figure 2-6 shows that if we slowed healthcare costs
growth from 2.5 percentage points to 1 percentage point starting in 2015—
which would be extremely difficult if not impossible to do, but is helpful as
an illustration—the result in 2050 would be a reduction of 10 percent GDP
in Medicare and Medicaid expenditures for the federal government relative
to no slowing in the cost growth rate. That 10 percent of GDP difference
is half of what the federal government spends today.
All of this may seem pretty challenging and is further complicated by
the fact that it is implausible that we will slow Medicare and Medicaid
growth in a sustainable way unless overall healthcare spending also slows.
The reason is that if all you did was, say, to reduce payment rates under
Medicare and Medicaid, and then try to perpetuate that over time without
a slowing of overall healthcare cost growth, the result would likely be
substantial access problems that would be inconsistent with the underlying
premise and public understanding of these programs. One therefore needs
to think about changes to Medicare and Medicaid in terms of the impact
they can have on the overall healthcare system.
From that perspective, there appears to be a very substantial opportu-
nity embedded in this long-term fiscal challenge facing the United States:
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THE NEED FOR BETTER MEDICAL EVIDENCE
25
Actual Projection
Differential of:
Percent of Gross Domestic Product
2.5 Percentage Points
20
1 Percentage Point
Beginning in 2025
15 1 Percentage Point
Beginning in 2015
10
5
0
1966 1972 1978 1984 1990 1996 2002 2008 2014 2020 2026 2032 2038 2044 2050
FIGURE 2-6 Effects of slowing the growth of spending for Medicare and
Medicaid.
SOURCE: Congressional Budget new 2-6.eps
Office, 2007.
the possibility of taking costs out of the system without harming health.
Perhaps the most compelling evidence underscoring this opportunity is
the significant variations across different parts of the United States that
do not translate into differences in health quality or health outcomes (Fig-
ure 2-7).
The question then becomes, why is this happening? To me, it appears
to be a combination of two things. One is the lack of information specifi-
cally about what works and what does not. The second thing is a payment
system, on both the provider and the consumer sides, that accommodates
the delivery of low-value or negative-value care.
On the consumer side, despite media portrayals to the contrary, the
share of healthcare expenditures paid out of pocket—which is basically
the relevant factor for evaluating the degree to which consumers are faced
with cost sharing—has plummeted over the past few decades, from about
33 percent in 1975 to 15 percent today (Figure 2-8). All available evidence
suggests that lower cost sharing increases healthcare spending overall, and
collectively we all pay a higher burden, although the evidence is somewhat
mixed on the precise magnitude of the effect by which lower cost sharing
raises overall spending.
This observation leads some analysts to argue that the way forward
is more cost sharing and a health savings account approach, and this can
indeed help to reduce costs. However, two things need to be kept in mind
in evaluating this approach. The first is that a significant amount of cost
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EVIDENCE-BASED MEDICINE
$7,200 to 11,600 (74) 6,30 0 to < 6,80 0 ( 55 ) 4,50 0 to < 5,80 0 (72 )
6,80 0 to < 7, 20 0 (45 ) 5,80 0 to < 6,30 0 ( 60 ) Not Populated
FIGURE 2-7 Medicare spending per capita in the United States, by hospital referral
region, 2003.
NOTE: The numbers in parentheses w 2-7.eps number of regions in each group.
ne indicate the
SOURCE: The Dartmouth Atlas Project, 2003.
sharing is involved in existing plans. Moving to universal health savings ac-
counts would thus not entail as great an increase in cost sharing, and there-
fore as much a reduction in spending, as you might think. Second, there is
an inherent limit to what we should expect from increased consumer cost
sharing because healthcare costs are so concentrated among the very sick.
For example, the top 25 percent most expensive Medicare beneficiaries ac-
count for 85 percent of total costs, and the basic fact that healthcare costs
are very concentrated among a small share of the population is replicated
in Medicaid and in the private healthcare system. To the extent that we in
the United States want to provide insurance, and insurance is supposed to
provide coverage against catastrophic costs, the fact that those catastrophic
costs are accounting for such a large share of overall costs imposes an in-
herent limit to the traction that one can obtain from increased consumer
cost sharing. In sum, increased cost sharing on the consumer side can help
to reduce costs, but it seems very unlikely to capture the full potential to
reduce costs without impairing health quality.
This leads us to the provider side. On the provider side, the accumu-
lation of additional information and changes in incentives could improve
efficiency in the delivery of health care. There is growing interest in com-
parative effectiveness research, and the original House version of the State
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7
THE NEED FOR BETTER MEDICAL EVIDENCE
35
33 %
30
25
26 %
20
Percent
15 17%
15%
13 %
10
5
0
1975 1985 1995 2005 2015
FIGURE 2-8 Share of personal healthcare expenditures paid out of pocket.
new 2-8.eps
Children’s Health Insurance Program legislation had some additional fund-
ing for comparative effectiveness research. Other policy makers seem inter-
ested in expanding comparative effectiveness research. We need, though, to
ask some hard questions about what we mean by comparative effectiveness
research and how it would be implemented.
The key issues are what kind of research is undertaken and the stan-
dard of evidence used. As Mark McClellan has noted, comparative effec-
tiveness research will very likely have to rely on nonrandomized evidence.
The reason is that it seems implausible that we could build out the evidence
base across a whole variety of different clinical interventions and practice
norms using only randomized control trials, especially if we want to study
subpopulations. On the other hand, economists have long been aware of
the limitations of panel data econometrics, where one attempts to control
for every possible factor that could influence the results—typically, that
attempt is far from perfectly successful. There is thus a tension between
using statistical techniques on panel data sets (of electronic health records,
insurance claims, and other medical data), which seems to be the only cost-
effective and feasible mechanism for significantly expanding the evidence
base, and the inherent difficulty of separating correlation and causation in
such an approach.
In terms of the budgetary effects of comparative effectiveness research,
a lot depends on both what is done and how it is implemented. If the effort
only involves releasing the results of literature surveys, the effects would
likely be relatively modest. If new research using registries or analysis of
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EVIDENCE-BASED MEDICINE
electronic health records is involved, there may be somewhat larger ef-
fects. The real traction, though, will come from building the results of
that research into financial incentives for providers. In other words, if
we move from a “fee-for-service” system to a “fee-for-value” one, where
higher-value care is awarded stronger financial incentives and low-value
or negative-value health care is penalized by smaller incentives, or perhaps
even penalties, the effects would be maximized. The design of such a system
is very complicated and difficult to implement, but this is where the greatest
long-term budgetary savings could come.
In conclusion, it is plausible to me that the combination of some in-
creased cost sharing on the consumer side and a substantially expanded
comparative effectiveness effort, combined with changes in the incentive
system for providers, offers the nation the most auspicious approach to
capturing the apparent opportunity to reduce healthcare costs at minimal or
no adverse consequences for health outcomes. The focus of this publication
is thus central to addressing the nation’s long-term fiscal challenge.
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