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Balas, E.A., Li, Z.R., Spencer, D.C., and others (1996,
January/February). "An expert system for performance-based direct
delivery of published clinical evidence." (AHCPR grant HS07715).
Journal of the American Medical Informatics Association
3(1), pp. 56-65.
The authors describe development of the Quality Feedback Expert
System (QFES), a tool for implementing clinical practice
guidelines. It is made up of three databases, supports
integration of recommendations from several guidelines into a
comprehensive and measurable quality improvement plan, analyzes
actual practice patterns and compares them with accepted
recommendations, and generates a confidential report to those who
significantly deviate from clinical recommendations. The
researchers demonstrated the feasibility of the practice pattern
analysis by the QFES in a sample of 182 urinary tract infection
cases from a primary care clinic, and found that in a set of
clinical activities, certain questions/ procedures were
associated with significant and unexplained variations. They
conclude that the QFES is a flexible tool for implementing
clinical guidelines in diverse and changing clinical areas
without the need for special program development.
Cassard, S.D., Patrick, D.L., Damiano, A.M., and others.
(1995, December). "Reproducibility and responsiveness of the
VF-14: An index of functional impairment in patients with
cataracts." (AHCPR grant HS06280). Archives of
Ophthalmology 113, pp. 1508-1513.
This study by the Cataract Patient Outcomes Research Team (PORT)
assesses the test-retest reliability and responsiveness of the
VF-14, which is an index of functional impairment in patients
with cataracts. They assessed the VF-14 in 552 patients 4 months
after they underwent cataract surgery in one eye and a subset of
these who did not subsequently undergo surgery for the second eye
by the 1-year followup. The VF-14 was reproducible in stable
patients during an 8-month period, and it was three times more
responsive to clinically significant changes in vision than the
Sickness Impact Profile, a generic health status measure.
Responsiveness of theVF-14 was greater in patients who reported
greater problems with vision before surgery.
Cohen, S.B., and Carlson, B.L. (1995). "Characteristics of
reluctant respondents in the National Medical Expenditure
Survey." Journal of Economic and Social Measurement 21,
This paper analyzes the factors which distinguished those
households that required special efforts to obtain their
participation in the Household Component of the 1987 National
Medical Expenditure Survey (NMES). The NMES provides national and
regional estimates of the health care use, expenditures, sources
of payment, and health insurance coverage of the U.S. civilian
noninstitutionalized population. Researchers from the Agency for
Health Care Policy and Research examined the quality of the data
obtained from these reluctant respondents and assessed the
likelihood of achieving their cooperation for all required rounds
of data collection. The results have significant implications for
design of future medical expenditure surveys. Reprints (AHCPR
Publication No. 96-R052) are available from AHCPR.
Iezzoni, L.I., Shwartz, M., Ash, A.S., and others (1996).
"Severity measurement methods and judging hospital death rates
for pneumonia." (AHCPR grant HS06742). Medical Care 34(1),
Payers and policymakers are increasingly examining hospital
mortality rates as indicators of hospital quality of care.
However, this study shows that perceptions of individual hospital
mortality rates vary, depending on the severity of illness
measures used to adjust actual mortality with expected mortality.
The researchers examined 14 severity of illness measurement
methods to judge hospital death rates for pneumonia at 105 acute
care hospitals nationwide. After adjusting for age, sex,
diagnosis, and severity of illness, 73 hospitals had observed
mortality rates that did not differ significantly from expected
rates according to all 14 severity methods; two had rates
significantly higher than expected for all 14 severity methods.
For 30 hospitals, observed mortality rates differed significantly
from expected rates when judged by one or more, but not all 14
severity methods. The 14 severity methods agreed about relative
hospital performance more often than expected by chance, but
perceptions of individual hospitals' mortality rates varied when
different severity adjustment methods were used for almost
one-third of facilities.
Katz, J.N., Chang, L.C., Sangha, O., and others (1996). "Can
comorbidity be measured by questionnaire rather than medical
record review?" (NRSA fellowship F32 HS00040). Medical
Care 34(1), pp. 73-84.
The number and severity of coexisting medical conditions
(comorbidity) of patients explains much of the variation in
clinical and economic outcomes of patients with the same disease.
This study explores whether comorbidity can be measured by
questionnaire rather than medical record review. The researchers
developed a brief comorbidity questionnaire that included items
corresponding to each element of the medical record-based
Charlson index and administered it to 170 inpatients. Although
the correlation between comorbidity measures was weaker in less
educated patients, the authors conclude that a questionnaire
version of the Charlson index is reproducible, valid, and offers
practical advantages over medical record-based assessments.
Katz, J.N., Punnett, L., Simmons, B.P., and others (1996,
January). "Workers' compensation recipients with carpal tunnel
syndrome: The validity of self-reported health measures." (AHCPR
grant HS06813). American Journal of Public Health 86(1),
This study compares the reliability, validity, and
responsiveness of self-reported measures of health-related
quality of life in recipients and non-recipients of workers'
compensation who have carpal tunnel syndrome. Patients with
carpal tunnel syndrome completed questionnaires at study
enrollment and 6 months later; scales measuring symptom severity,
functional status, and satisfaction were included. The internal
consistencies for each scale were high and virtually identical in
recipients and nonrecipients of workers' compensation. The
correlations between self-reported and objectively measured grip
strength were .32 in recipients and .30 in nonrecipients,
regardless of whether the recipients were out of work. The
researchers conclude that the reliability, validity, and
responsiveness of these measures were comparable in nonrecipients
and recipients of workers' compensation, and that these data
support the use of self-report measures in studies of workers.
McDonald, C.J., Overhage, M., Tierney, W.M., and others.
(1996, January). "The promise of computerized feedback systems
for diabetes care." (AHCPR grant HS07719). Annals of Internal
Medicine 124 (1 pt 2), pp. 170-174.
Most current medical uses of computer-based feedback control
are open loop, where a human is interposed between the suggested
intervention and the delivered treatment. Open-loop systems have
already been used in diabetes care to suggest insulin dosage
adjustments and treatments for hypercholes-terolemia and to
remind physicians of various interventions to reduce the
complications of diabetes mellitus. However, existing
applications have only scratched the surface, according to these
authors. Many more facets of diabetes management could be
standardized and assisted by open-loop control systems if the
management rules could be more exactly specified. New primary
studies and decision analyses are needed to define the optimal
use of some interventions.
Robinson, J.C., and Gardner, L.B. (1995). "Adverse selection
among multiple competing health maintenance organizations."
(AHCPR grant HS06815). Medical Care 33(12), pp. 1161-1175.
This study examines risk selection by nine health plans
competing for 16,182 employees of one large firm in 1989: one
conventional fee-for-service plan, one group-model health
maintenance organization (HMO), and seven network and independent
practice model HMOs. The researchers developed and compared
measures of risk using weights based on HMO and fee-for-service
expenditure data. Predicted annual expenditures per enrollee
exhibited a 23 percent range from lowest (favorable selection) to
highest (adverse selection) risk plans using the HMO weights and
a 17 percent range using fee-for-service weights. The
fee-for-service plan and group-model HMO with large enrollments
had risk mixes near the center of the spectrum. Smaller HMOs
exhibited the extreme forms of both favorable and adverse
Spector, W.D. (1996). "Functional disability scales." In B.
Spilker (ed.), Quality of Life and Pharmacoeconomics in
Trials, Second Edition. Philadelphia: Lippincott-Raven
Publishers, pp. 133-143.
The periodic assessment of disabilities has become an
part of the standard medical evaluation of the elderly. This book
chapter by William D. Spector, Ph.D., of the Center for
Organization and Delivery Studies, Agency for Health Care Policy
and Research, reviews a small number of functional disability
scales that have received acceptance in the clinical and research
arenas and have demonstrated sufficient reliability and validity.
He emphasizes scales that include one type of disability measure,
and points out that no scale is best for all purposes and that a
scale should be chosen based on its specific purpose. Moreover,
the properties of the scale should be carefully studied after
implementation to assure that expected relationships between
items exist. This is particularly important if the scale is
applied to a new population or if modifications have been made.
Dr. Spector cautions researchers about constructing new scales or
using scales that have not been validated and about combining
items in simplistic ways without doing appropriate scalability
and validity analyses.
Tsevat, J., Solzan, J.G., Kuntz, K.M., and others (1996).
"Health values of patients infected with human immunodeficiency
virus: Relationship to mental health and physical functioning."
(AHCPR grant HS06673) Medical Care 34(1), pp. 44-57.
According to this study, most AIDS patients are unwilling to
trade any years of life, no matter how ill they are, for a
shorter time in perfect health. The researchers used three health
status measures and three health value measures to ask 139
patients infected with HIV about their health status and how they
valued their health. Each participant was interviewed twice at
6-month intervals. As expected, the health status of HIV-infected
patients who remained asymptomatic or remained symptomatic but
did not develop AIDS changed little over 6 months, whereas health
status deteriorated in patients with AIDS and those in whom HIV
infection progressed. In contrast, health values, and in
particular time-tradeoff scores, remained stable even in the face
of changes in health status and disease progression. These
findings suggest that either patients gradually acclimated to
their deteriorating health state or they redefined their concept
of "excellent health," conclude the researchers.
Zhou, Z.H. (1996, January-March). "Empirical Bayes combination
of estimated (AHCPR grant HS08559). areas under ROC curves using
estimating equations." Medical Decision Making 16, pp.
Evaluating the accuracies of diagnostic tests in detecting the
presence of disease is very important for both quality of care
and cost containment. A receiving operating characteristics (ROC)
curve allows the study of the inherent discrimination capability
of a diagnostic test. The empirical Bayes (EB) method does not
assume that individual studies all have the same true ROC area
and provides a simple way to express study-level heterogeneity
with a two-stage model. The author presents a synthesis of the EB
method and the method of estimating equations to combine
individual ROC area estimates from different studies of the same
diagnostic test into a single estimate.
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AHCPR Publication No. 96-0055
Current as of April 1996