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provider, or society also is an outcome in health services
research. Large clinical trials often include cost analysis.
the costs of various treatments. Cantor and associates
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Research in Primary Care and the Departments of Medicine, Psychiatry,
and Nursing, Duke University, Durham, North Carolina (H.B.B.).
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doideveloped a Markov model to compare the 5-year costs ofnquiries to Kelly W. Muir, Duke University Medical Center, Boxction in the business and policy community. Health
vices research allows educators to evaluate the success of
h programs.
For example, the Ocular Hypertension Treatment Study
investigators analyzed the cost effectiveness of treating
versus observing patients with ocular hypertension. Cost
analysis revealed that the treatment of patients with
intraocular pressure of 24 mm Hg or more and 2% or more
annual risk of the development of glaucoma is likely to be
cost effective.6 Cost analysis can also be used to compare
cepted for publication July 13, 2010.
rom the Duke University Eye Center, Durham, North Carolina
W.M., P.P.L.); and the Durham VAMC Center for Health ServicesSERIES ON EP
ealth Services Research and H
State of Oph
KELLY W. MUIR, HAYDEN B. B
EALTH SERVICES RESEARCH SPANS MULTIPLE
fields of scientific inquiry and informs healthcare
policy making on various levels. Although both
ssic epidemiology and health services research are con-
ned with populations, health services research differs in
emphasis on the structure, process, and effects of health
vices as opposed to focusing on disease prevalence and
vention. Likewise, health services research differs from
nical epidemiology, which emphasizes the causation and
tural history of disease. As a multidisciplinary field,
wever, health services research incorporates epidemiol-
y, as well as economic and social science, into the
alysis of healthcare delivery (Figure 1).
EXAMINING STRUCTURE, PROCESS,
AND EFFECTS
E STRUCTURE OF HEALTHCARE SERVICES RELATES TO
ues such as physician workforce considerations. For
ample, while evaluating patterns of care, trends in work
ort, and models of population growth, Lee and associates
ncluded that ophthalmology will experience substantial
allenges in manpower in the next 10 to 20 years.1
jections for the ophthalmology workforce demonstrate
w health services research can inform us about the
ure in addition to evaluating the healthcare delivery of
present.
The study of structure also pertains to medical educa-
n. Surgical fields such as ophthalmology may benefit
m technological advances in simulation of medical
cedures. Simulation-based surgical training is one ave-tre2, Durham, NC 27710; e-mail: kelly.muir@duke.edu
PUBLISHED BY ELSE2-9394/$36.00
:10.1016/j.ajo.2010.07.006EMIOLOGY
w It Can Inform the Current
almology
ORTH, AND PAUL P. LEE
Health services research also evaluates the process by
ich healthcare is provided. Process issues include access
care and use of services and how such variables may
fer for specific populations. For example, in reviewing
es of medical and surgical treatment for glaucoma from
92 to 2002 among Medicare beneficiaries, Stein and
ociates found that Latino and Asian beneficiaries with
ucoma were less likely to receive treatment than were
ites.2
In the context of Health services research, effects includes
outcomes of health care. Outcomes assessment can take
ny forms. Traditionally, outcomes of interest in the
dical literature were mortality or physiologic measures
defined by diagnostic tests. In ophthalmology, tradi-
nal outcomes include legal blindness and loss of acuity
visual field as well as physiologic measures such as
raocular pressure or retinal thickness. More recently,
estigators have included patient-centered outcomes such
performance measures (reading speed, mobility) and qual-
-of-life indicators. In fact, ophthalmology was one of the
t fields to develop instruments to quantify disease-specific
ality of life. The VF-14, an index of visual functioning
use in patients with cataracts,3 was found to predict
f-reported satisfaction with vision better than visual
ity or a general health status score.4 More recently, the
tional Eye Institute developed the Visual Function
estionnaire, which has been used to evaluate the impact
visual function by a multitude of ophthalmic condi-
ns.5 Quality-of-life outcomes now are included com-
nly as secondary end points in major clinical trials such
the Collaborative Initial Glaucoma Treatment Study.
The cost of care from the perspective of the patient,ating glaucoma with medications, laser trabeculoplasty,
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76filtering surgery and found that laser trabeculoplasty
ulted in the least cost.7
Recently, studies of comparative effectiveness have
erated much discussion in the health services research
mmunity. Comparative effectiveness simply means com-
ring how effective different treatment strategies are at
proving health outcomes. In February, an article in the
w England Journal of Medicine stated that “the American
covery and Reinvestment Act of 2009 authorizes the
penditure of $1.1 billion to conduct research comparing
inical outcomes, effectiveness, and appropriateness of
ms, services, and procedures that are used to prevent,
gnose, or treat diseases, disorders, and other health
nditions.’”8 Supporters of comparative effectiveness re-
rch argue that we can contain healthcare costs by
iting less-effective treatment options.
METHODS IN HEALTH SERVICES
RESEARCH
AUSE HEALTH SERVICES RESEARCH DRAWS ON DIFFER-
t fields of scientific inquiry, research methods are di-
rse. Health services research can be basic (eg, the
velopment of a vision-related quality-of-life instrument)
applied (eg, the use of the quality-of-life instrument to
mpare the outcomes of 2 treatment strategies). Study
signs used in health services research can include sec-
dary data analysis, survey research, or qualitative re-
rch including focus groups and interviews. Advanced
tistical techniques such as propensity scores and case-
x adjustments often are needed to address large numbers
variables in real-world data. Health service research
estigators also are involved in the development of
erventions for patients, providers, and the healthcare
tem. The evaluation of these interventions and, if
cessful, their broad-scale implementation also are fields
URE 1. Schematic illustrating the interactions between
ic science research, clinical research, and health services
earch.study in health services research. tig
AMERICAN JOURNAL OF O2IMPACT OF HEALTH SERVICES
RESEARCH
EDUCING HEALTH DISPARITIES: Epidemiology and
alth services research perform complementary roles in
ucing health disparities. Epidemiologic studies that
n a large population of varying socioeconomic strata
h as the Baltimore Eye Survey have the power to
ture disparities in disease prevalence that may be
ssed in smaller studies. For example, the investigators in
Baltimore Eye Survey reported that African Americans
re more likely to be blind from cataracts than were
ites.9 One approach to explore why such a disparity
ists is to examine the structure and process of healthcare
livery to different populations. Williams and associates
amined longitudinal rates of cataract surgery for more
n 8000 older Americans and found that African Amer-
ns were less likely to undergo cataract surgery.10
NFORMING PUBLIC POLICY: Information gained from
alth services research has the potential to change
althcare policy on the local and the national level. Of
rticular interest in the United States is the growing
mber of older Americans afflicted with age-related
cular degeneration. In a study involving Medicare
ims data from more than 30 000 people 68 years of age
d older diagnosed with age-related macular degenera-
n, Wysong and associates found that those with age-
ated macular degeneration have significantly greater
ual and functional impairment than their aged-matched
ers.11 Information about functional impairment in large
pulations such as in this study allows policy makers to
ke better-informed decisions about resource allocation.
the state level, in the 1970s, several states revisited
tificate-of-need programs because of research suggesting
t such programs were ineffective at reducing costs.12
EVELOPING AND EVALUATING PRACTICE GUIDE-
ES: The development of clinical practice guidelines has
lved from the advice of experts to the rigorous evaluation
the best evidence-based medicine available. Combining
tcomes assessment and cost analysis is one way in which
alth services research can improve guideline development.
ditionally, Health Services Research investigators can
ess the effectiveness of practice guidelines. For example, in
opulation of Medicare beneficiaries from 1994 through
02, diabetics who received ophthalmic care consistent with
ctice guidelines experienced lower rates of onset of low
ion and blindness than did others.13
CHALLENGES IN HEALTH SERVICES
RESEARCH
ALTH SERVICES RESEARCH ADDRESSES COMPLEX PROB-
s, creating logistical and analytic challenges for inves-
ators. Secondary database analysis may provide a large
PHTHALMOLOGY DECEMBER 2010