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Variations: Wennberg Perspective Web Exclusive
P E R S P E C T I V E S
V A R I A T I O N S
W E B E X C L U S I V E
7 October 2004
Perspective:
Practice Variations
And Health Care Reform:
Connecting The Dots
A focus on medical
error is preventing sufficient focus on improving the quality of patient
decision making to reduce practice variations (and costs) in today’s
health care system.
By John E. Wennberg
ABSTRACT:
Unwarranted variation is a ubiquitous feature of U.S.
health care. Remedies for variations exist, and several are described in the
current collection of Health Affairs papers. Several obstacles
stand in the way of widespread adoption of these remedies: (1) a quality agenda
that has yet to focus on improving the quality of patient decision making;
(2) economic incentives that do not reward exemplary practice; and (3) the
poor state of clinical science. Medicare reform legislation creates the opportunity
for a demonstration project to redesign health care to address these barriers.
We also must grapple with the cultural bias that more care is better and that
physicians must know best.
Several papers in this Health
Affairs collection show once again that unwarranted variation—variation
not explained by illness, patient preference, or the dictates of evidence-based
medicine—is a ubiquitous feature of U.S. health care.1 As
shown in several of these papers, health care systems fail to provide in full
measure such simple life-saving, morbidity-sparing interventions as immunizations,
diabetic glucose monitoring, and the use of drugs for those with heart attacks.
Every region and every state exhibits underuse of effective care, some more
so than others.2 James Weinstein and
his colleagues provide further evidence that the incidence of discretionary
surgery, the use of which should depend on patient preference, is unduly influenced
by local physician opinion, which has resulted in striking long-term variation
in the risk of surgery among local regions—the “surgical signature” phenomenon.3 Elliott
Fisher and his colleagues show that among the chronically ill, the frequency
of physician visits, diagnostic testing, and hospitalization and the chances
of being admitted to an intensive care unit (ICU) depend largely on where
patients live and the health care system they routinely use, independent of
the illness they have or its severity.4 Katherine
Baicker and her colleagues show that variation affects minority groups as
it does white Americans, which clouds the interpretation of racial and ethnic
disparities based on national average rates.5
While noting that the U.S. supply of physicians grew remarkably
over the past twenty years, David Goodman shows that growth in aggregate supply
does not “cure” variations: In 1999 the per capita supply of generalist
physicians varied more than twofold and that of medical specialists more than
fivefold among regions.6 I and my colleagues
document that Medicare spending varies more than twofold among regions, but
more spending is not associated with better quality, as measured by reduced
underuse of effective care, or, surprisingly, with more major surgery.7 Greater
per capita spending buys more intensive intervention among patients with chronic
illness: Those who live in high-cost regions experience more visits to medical
specialists, tests, hospitalizations, and ICU stays than their counterparts
living in low-cost regions. And because of the way Medicare is financed, regions
with low costs end up subsidizing a sizable proportion of the care for those
living in high-cost regions.
The irony, as Fisher and his colleagues show, is that
patients with similar chronic illnesses who live in high-cost regions, including
those who receive most of their care from prominent academic medical centers
(AMCs), do not have better health care outcomes than patients living in low-cost
regions.8 In other words, the patterns
of practice in managing chronic illness in low-cost regions do not appear
to result in the withholding of valuable care (health care rationing); rather,
systems of care serving high-cost regions are inefficient because they are
wasting resources.
Possible remedies. The
news, however, is not uniformly bad. Remedies for unwarranted variation exist,
and several are described in these papers. The underuse of effective care can
be reduced through feedback of information and by putting in place the infrastructure
required to assure the systematic implementation of practice guidelines.9 Surgical
processes can be improved with measurable influence on severity-adjusted case
fatality rates.10 Medical
errors associated with low-volume surgery could be reduced by regionalization
(although, as Justin Dimick and his colleagues point out, some regions have
too few cases to meet minimum volume criteria).11
Annette O’Connor and her colleagues summarize a
growing literature showing that for preference-sensitive care involving elective
surgery, the role of the patient in influencing the choice of treatments can
be modified and improved by the introduction of high-quality decision aids
that encourage shared decision making.12 Weinstein
and his colleagues describe a strategy for conducting clinical trials based
on shared decision making that improves the scientific understanding of the
outcomes of elective surgery and explicitly takes patient preference into
account.13 As
described by Karen Sepucha and her colleagues, quality measures can be developed
to assess the degree to which shared decision making has occurred.14 The
good news for payers is that the evidence so far suggests that not only do
decision aids improve the quality of patient decision making, but also their
use seems to reduce the incidence of elective surgery and result in lower
costs.
The overuse of supply-sensitive care can be addressed
through improvements in managing chronic illness and by paying attention to
the capacity of a health care system relative to the size of the population
it serves.15 As I and my colleagues
show, population-based, provider-specific measures of performance based on
Medicare claims can be used to describe the impact of decisions made by clinicians
and administrators of fee-for-service (FFS) health care organizations on the
populations they serve.16 Performance
measures include per capita costs, resources used in managing chronic illness
(such as the per capita numbers of full-time-equivalent physicians used),
and utilization rates. Thus, at least in theory, health care organizations
serving FFS Medicare beneficiaries can adopt a population-based strategy for
managing resources and utilization that is similar to the strategies used
by staff-model or prepaid group practice health maintenance organizations
(HMOs) such as Kaiser Permanente.
Persistence of variation. Remedies
have been applied sporadically, however. One reason is that the quality agenda
has yet to focus on improving the quality of patient decision making—that
is, on increasing the extent to which patients make genuinely informed, preference-based
choices among treatment options. The concentration instead is on medical errors.
The importance of focusing on both issues simultaneously can be seen in the
potential for unintended consequences of efforts to set minimum volume standards
for performing discretionary surgery, to reduce the risk of death following
surgery. (Hospitals with higher volume tend to have lower case fatality rates.)
Among regions or populations served by a given health care organization, the
case fatality rate is only one of two factors that determine variations in
the underlying population-based death rate. The other is the risk of undergoing
surgery—that is, the population-based surgery rate. For example, in
the case of bypass surgery, the rate of exposure to surgery (surgery per capita)
and the case fatality rate are of about equal importance in explaining deaths
per capita associated with bypass surgery.17 Thus,
in assessing the causes of variation in population-based death rates associated
with surgery, the quality of the decisionmaking process that determines the
use of surgery is as important a factor as the quality of the process of surgical
care that determines the case fatality rate. Setting minimum volume standards
will inevitably cause some low-volume hospitals or physicians to
seek to increase the numbers of elective procedures they perform. Without
a simultaneous focus on improving the quality of patient decision making to
assure that patients’ rather than providers’ opinions determine
the demand for elective surgery, one must expect a net increase in the numbers
of patients undergoing surgery who have not made an informed choice. Moreover,
as the per capita rate of surgery increases, the population-based death rate
within thirty days of bypass surgery may also rise.
Another reason for the persistence of unwarranted variation
is the absence of economic incentives that reward providers with exemplary
patterns of practice. The “pay for quality” movement has concentrated
primarily on rewarding providers who increase utilization rates for effective
care (such as the percentage of diabetics who get annual eye examinations).
Modifying the reimbursement system to promote shared decision making and higher-quality
patient decision making for preference-sensitive care presents a much greater
challenge. Under present circumstances, the relative frequency of use of discretionary
surgery is remarkably stable over longer periods of time.18 Providers
depend on the revenues generated from these patterns of practice. In light
of the evidence that informed patients may demand less discretionary surgery
than the amount now provided, the introduction of shared decision making may
pose a serious threat to the financial integrity of health care
organizations whose workload is in disequilibrium with “true” (that
is, patient-driven) demand. The economic incentives now inherent in Medicare’s
FFS reimbursement system must be modified if shared decision making is to
be successfully implemented among enrollees in traditional Medicare.
A similar if not more complicated set of issues pertains
to reduction in the overuse of supply-sensitive care when managing cohorts
of chronically ill Medicare patients. Here, the utilization rate is closely
related to the per capita supply of resources. Reduction in use thus requires
a reduction in acute care capacity toward the population-based benchmarks
provided by efficient providers. Again, the payment system is not designed
to reward clinicians and administrators who wish to adopt the population-based
approach: The reimbursement system is designed to pay for utilization; net
savings that may result from more rational management revert to the payer,
not to the health care organization. Given the dependency of health care organizations
on utilization to generate the budgets to pay for infrastructure, amortize
bond market debt, or reward equity investments, the reduction of overuse of
supply-sensitive care will be difficult if not impossible to manage in the
absence of reform of the reimbursement system.
There is yet another reason for only patchy progress in
reducing unwarranted variation: the poor state of clinical science. Biotechnology
is producing a growing number of technological interventions, and clinicians
generate a plethora of theories about how they should be applied. But the
basic mechanisms to assure the orderly evaluation of technologies and clinical
theories simply are not in place. Clinical medicine is thus awash in novelty,
but without the capacity to distinguish what truly works. My paper and that
of Fisher and colleagues illustrate that the problem is generic, affecting
our most prestigious scientific institutions.19
Part of the problem is that academe has few incentives to devote resources and
talent to deal with the contradictions in their own patterns of practice.
Without reform in federal science policy that gives the evaluation agenda
high priority, intellectual and scientific confusion will continue to contribute
to the problem of unwarranted variations.
Three needed reforms. The
opportunity to provide systematic remedy thus depends on three reforms. First,
the quality agenda must be extended beyond effective care; the agenda should
also address unwarranted variation in preference-sensitive treatments such
as discretionary surgery and the overuse of physician and acute care hospital
services in managing chronic illness. Second, reform of the payment system
must be undertaken to enable providers to deal with the complicated and interrelated
financial, organizational, and behavioral issues that need to be resolved
if the quality of patient decision making is to be improved and inefficiencies
and waste in the treatment of chronic illness remedied. Third, AMCs and the
National Institutes of Health (NIH) must respond to the glaring weaknesses
in the scientific basis for clinical decision making by undertaking the systematic
evaluation of the everyday practices of medicine.
As discussed in the commentary by Paul Harrington, Section
646 of the Medicare Prescription Drug, Improvement, and Modernization Act
(MMA) of 2003 creates the opportunity to undertake a demonstration project
to redesign health care, to address each of these barriers to progress.20
It asks participating provider organizations to address unwarranted variations
in all three categories. It contains provisions for the reform of payment
systems to promote the efforts of participating health care organizations
to meet these goals. And it calls for the active involvement of the NIH and
the Agency for Healthcare Research and Quality (AHRQ) in helping participating
providers undertake outcomes research to evaluate variations in their own
patterns of practice and improve the scientific basis for clinical decision
making.
I am hopeful that the provisions of Section 646 will lead
to a redesign of clinical practice that will serve as a model for wide replication.
Variations, however, are remarkably resistant to change. Ultimately, the opportunity
for a broad-based reform is constrained by our beliefs and expectations. Our
culture is embedded with a strong belief that more is better and that physicians
know best. The study of practice variations uncovers a very different, more
nuanced reality. Making the practice-pattern story real to Main Street would
be a giant step forward in building the constituency for change.
The author extends his thanks and appreciation to
his many colleagues who have contributed to variations research over the years.
NOTES
1. A special collection of papers and commentaries on variations
is available at content.healthaffairs.org/cgi/content/full/hlthaff.var.140/DC1.
2. K. Baicker et al., “Who You Are and Where You Live: How
Race and Geography Affect the Treatment of Medicare Beneficiaries,” Health
Affairs, 7 October 2004, content.healthaffairs.org/cgi/content/abstract/hlthaff.var.33.
For evidence on the extent of underuse of effective care, see also K. Baicker
and A. Chandra, “Medicare Spending, the Physician Workforce, and Beneficiaries’ Quality
of Care,” Health Affairs, 7 April 2004, content.healthaffairs.org/cgi/content/abstract/hlthaff.w4.184 (9
September 2004); and E.A. McGlynn et al., “The Quality
of Health Care Delivered to Adults in the United States,” New
England Journal of Medicine 348, no. 26 (2003): 2635– 2645.
3. J.N. Weinstein et al., “Trends and Geographic Variations
in Major Surgery for Degenerative Diseases of the Hip, Knee, and Spine,” Health
Affairs, 7 October 2004, content.healthaffairs.org/cgi/content/abstract/hlthaff.var.81.
4. E.S. Fisher et al., “Variations in the Longitudinal Efficiency
of Academic Medical Centers,” Health Affairs, 7
October 2004,
content.healthaffairs.org/cgi/content/abstract/hlthaff.var.19.
5. Baicker et al., “Who You Are and Where You Live.”
6. D.C. Goodman, “Twenty-Year Trends in Regional Variations
in the U.S. Physician Workforce,” Health Affairs, 7
October 2004,
content.healthaffairs.org/cgi/content/abstract/hlthaff.var.90.
7. J.E. Wennberg et al., “Use of Medicare Claims Data to Monitor
Provider-Specific Performance among Patients with Severe Chronic Illness,” Health
Affairs, 7 October 2004, content.healthaffairs.org/cgi/content/abstract/hlthaff.var.5.
8. Fisher et al., “Variations in the Longitudinal Efficiency.”
9. See S.F. Jencks, E.D. Huff, and T. Cuerdon, “Change in the
Quality of Care Delivered to Medicare Beneficiaries, 1998–1999 to 2000– 2001,” Journal
of the American Medical Association 289, no. 3 (2003): 305–312.
10. See, for example, G.T. O’Connor et al., “A Regional
Intervention to Improve the Hospital Mortality Associated with Coronary Artery
Bypass Graft Surgery, The Northern New England Cardiovascular Disease Study
Group,” Journal of the American Medical Association 275,
no. 11 (1996): 841–846.
11. J.B. Dimick, S.R.G. Finlayson, and J.D. Birkmeyer, “Regional
Availability of High-Volume Hospitals for Major Surgery,” Health
Affairs, 7 October 2004, content.healthaffairs.org/cgi/content/abstract/hlthaff.var.45.
12. A.M. O’Connor, H.A. Llewellyn-Thomas, and A.B. Flood, “Modifying
Unwarranted Variations in Health Care: Shared Decision Making using Patient
Decision Aids,” Health Affairs, 7 October
2004, content.healthaffairs.org/cgi/content/abstract/hlthaff.var.63.
13. Weinstein et al., “Trends and Geographic Variations.”
14. K.R. Sepucha, F.J. Fowler Jr., and A.G. Mulley Jr., “Policy
Support for Patient-Centered Care: The Need for Measurable Improvements in
Decision Quality,” Health Affairs, 7
October 2004, content.healthaffairs.org/cgi/content/abstract/hlthaff.var.54.
15. T. Bodenheimer, E.H. Wagner, and K. Grumbach, “Improving
Primary Care for Patients with Chronic Illness: The Chronic Care Model, Part
2,” Journal of the American Medical Association 288,
no. 15 (2002): 1909–1914. Alain Enthoven was the first to point out
the importance of “private sector health planning” as a management
tool used by staff- or group-model HMOs to control capacity (and thereby utilization
rates for supply-sensitive care). See A.C. Enthoven, Theory
and Practice of Managed Competition in Health Care Financing (Amsterdam:
Elsevier North-Holland, 1988).
16. Wennberg et al., “Use of Medicare Claims Data.”
17. Among the 100 largest hospital referral regions (HRRs), the correlation
for Medicare Part A enrollees between bypass operations per capita and per
capita deaths associated with surgery was .737 (p < .0001);
the association between case fatality (percentage of procedures ending in
death) and per capita deaths associated with surgery was .735 (p < .0001);
and the association between case fatality rates and bypass surgery per capita
was .113 (p < .0001).
The data are for 1989–2001, from the Dartmouth Atlas
of Health Care, www.dartmouthatlas.org (23 August 2004).
18. Weinstein et al., “Trends and Geographic Variations.”
19. Wennberg et al., “Use of Medicare Claims Data”; and
Fisher et al., “Variations in the Longitudinal Efficiency.”
20. P. Harrington, “Quality as a System Property: Section 646
of the Medicare Modernization Act,” Health Affairs, 7
October 2004,
content.healthaffairs.org/cgi/content/abstract/hlthaff.var.136.
John Wennberg (john.wennberg{at}dartmouth.edu) directs the Center for the Evaluative
Clinical Sciences at Dartmouth Medical School in Hanover, New Hampshire.
DOI: 10.1377/hlthaff.var.140
©2004 Project HOPE–The People-to-People Health Foundation, Inc.
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