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Patient Outcomes Research Team. Principal Investigator: Earl P.
Steinberg, M.D., M.P.P., The Johns Hopkins University.
Grant Number: HS 06280.
Project Period: September 1989 to February 1995.
The cataract PORT assesses variations in the management of
cataract, their relationship to differences in both short- and long-term health care outcomes of
major concern to patients, and cost effectiveness issues. The PORT developed an index of the
effects of cataract on a patient's ability to function that is being widely adopted.
Cataract PORT Contents (Spring 1995)
Introduction
Cataract (clouding of the eye lens), which is part of the normal
aging process, is the leading cause of blindness in the United States. Although there is no known
treatment to prevent cataracts from forming or progressing, surgical removal of cataracts is
highly
effective. Cataract removal is the most common surgical procedure performed on the elderly.
Medicare beneficiaries undergo more than 1.35 million cataract extractions each year, at an
estimated cost of $3.4 billion.
The cataract PORT is one of the large, multi-disciplinary projects of the first generation of
MEDTEP research. The cataract PORT includes:
- Comprehensive review and synthesis of the published literature on cataract management.
- Assessment of patients' medical and functional status before and after cataract
removal.
- National surveys of ophthalmologists, optometrists, anesthesiologists, and internists to
assess cataract management and the beliefs underlying current practice patterns.
- Analyses of Medicare claims data on cataract surgery patients to identify and assess patterns
of management, costs, and outcomes.
- A decision model, incorporating demographic changes expected over the next 30 years, to
predict the impact of these changes on the cost effectiveness of cataract care and to help identify
the best strategies for specified categories of patients.
Return to Cataract PORT Contents
Findings
The PORT developed a new measure of cataract-related visual impairment because visual acuity
alone, used traditionally, inadequately measures the need for and outcomes of cataract surgery.
In fact, the AHCPR-supported cataract clinical practice guideline concluded that, regardless of
objectively measured visual acuity, cataract surgery is indicated when a patient believes that the
functional disability caused by the cataract is troublesome enough to justify the risk of removal.
The new measure—the VF-14—is a visual function index to measure
cataract-related
impairment of abilities to perform 14 everyday activities, including reading and driving. The
PORT tested the VF-14 by following 766 patients planning to have cataract surgery for the
first
time.
Findings showed that the VF-14 was a much stronger predictor of patients'
self-reported
satisfaction with their vision than were visual acuity or general health status scores. The
VF-14
index appears to be a sensitive and reliable measure of the impact of cataract on visual function.
As a result, it can be used to help determine the value of cataract surgery for specific patients.
In a study of more than 500 patients 4 months after cataract removal, changes in patients' ratings
of satisfaction with their vision correlated more strongly with changes in VF-14 scores than
with
changes in visual acuity. Compared with other outcome measurements, a changed VF-14
score
was also the strongest predictor of changes in patients' satisfaction with their vision.
PORT investigators also evaluated the literature on safety and effectiveness of cataract
removal. They found that:
- Most published studies on cataract surgery outcomes lacked a control or comparison
group.
- Patient selection biases made it difficult to determine whether results could be
generalized.
- Complications were not adequately described, precluding assessment of their clinical
significance.
An analysis of nearly 14,000 Medicare patient records suggests that patients who underwent
yttrium aluminum garnet (YAG) laser surgery have four times the risk of a detached
retina—which can lead to permanent blindness—than patients who did not have YAG
laser
surgery. YAG laser surgery is commonly used to correct clouding of the capsule behind the
lens after cataract removal. The finding suggests that YAG laser surgery should not be used as a
preventive measure and that the risks involved should be explained to patients considering the
procedure.
This analysis has important limitations—such as the data not showing if YAG laser
surgery
and cataract surgery were both performed on the same eye. Because of these limitations, the
cataract PORT is now performing an innovative case-control study of risk factors (including
YAG laser surgery) for retinal detachment.
In another study, the PORT found that the rate of endophthalmitis, an eye infection, had
decreased significantly in 1987 compared with 1984. During that same period, cataract surgery
shifted from inpatient to outpatient care.
To estimate the frequency and costs of services provided with cataract surgery, another study
analyzed the experience of more than 57,000 Medicare beneficiaries who underwent cataract
extractions in 1986 and 1987. Projections for current costs were made using 1991 charges
allowed by Medicare. The median allowed charge for a "typical" cataract surgery episode was
approximately $2,500. Major determinants of Medicare costs were found to be the rate of
performance of cataract surgery and of YAG laser surgery and the charges allowed for these
procedures. These findings were incorporated into AHCPR's clinical practice guideline.
Return to Cataract PORT Contents
Dissemination
One avenue for dissemination of PORT research findings is involvement in developing
AHCPR-supported clinical practice guidelines. The cataract PORT had a close working
relationship with the panel that developed the cataract guideline. Five published cataract PORT
studies were considered by the panel developing the guideline, and several PORT analyses,
including cost assessments, were incorporated into the guideline.
In addition, the cataract PORT redesigned several ongoing studies to ensure that issues of
high priority to the panel, but for which insufficient data were available, would be addressed by
the PORT. These issues include the effects on outcomes of different types of anesthesia, and
care after cataract surgery.
To date, the cataract PORT has had 19 articles published in professional journals, including
the Archives of Ophthalmology, Medical Care, Ophthalmology, and the Journal of
Clinical Epidemiology. PORT members have presented their findings at more than 50 meetings of
professional groups, such as the American Academy of Ophthalmology, the Association for
Research in Vision and Ophthalmology, the National Eye Institute, and the International
Congress of Eye Research. PORT members have testified before the U.S. Senate Select
Committee on Aging and the Subcommittee on Health of the House Ways and Means
Committee.
Other dissemination strategies include alliances with ophthalmology societies and with
patient interest groups such as the American Association of Retired Persons.
Dissemination Summary: Variations in Cataract Management PORT
| Presentations: | 58 |
| Professional Articles: | 19 |
| Health Industry Articles: | 11 |
| Professional Mentions: | 19 |
| Consumer Print: | 42 |
| Consumer Broadcast: | 1 |
| Total: | 150 |
Return to Cataract PORT Contents
Implications
The PORT's studies have identified issues related to surgical techniques and practices that have
important implications:
- Perhaps most important is the PORT's development of the VF-14 to quantify patients'
functional impairment related to vision. Better than other measures, this tool allows
ophthalmologists and patients to evaluate the need for, and potential benefit of, cataract
surgery.
- The PORT has helped to determine the level of benefit in performing cataract surgery on
the second eye, and the characteristics of patients most likely to benefit from surgical
treatment.
- The suggestion of increased risk found by the PORT of retinal complications after YAG
laser surgery should be considered by doctors and patients before deciding to perform this
procedure. YAG laser surgery remains the treatment of choice for patients whose vision or
quality of life is impaired because of clouding of the capsule behind the lens after cataract
removal. Although the issue is still under study, the PORT results may lead doctors and patients
to defer YAG laser surgery until patient impairment is severe enough to warrant the increased
risks.
- The American Academy of Ophthalmology is developing a national outcomes data base for
eye care, which will initially include data on cataract surgery. AHCPR supported the basic
outcomes research through the PORT, producing practical tools (such as the VF-14) that
will be
used to collect data. Dr. Steinberg, the PORT's Principal Investigator, is designing and
managing the data base. When the data base becomes operational—tentatively November
1995—practicing ophthalmologists will for the first time have immediate access to current,
hard
data on how cataract patients are managed and on cataract surgical outcomes.
- According to the PORT's national surveys of physicians who manage cataracts, many
believe that medical tests performed before cataract surgery, such as chest x-rays and
electrocardiograms, have
little benefit. AHCPR is supporting a new PORT project that will assess the value of
pre-operative medical testing for cataract patients.
AHCPR awarded a grant in July 1991 to expand the PORT study of cataract extractions to
Canada, Denmark, and Spain. This international project expands the range of practices beyond
those observed in the United States and permits comparisons of a range of patient outcomes.
Return to Cataract PORT Contents
Bibliography
Bass, E.B., Steinberg, E.P., Luthra, R., Schein, O.D., Javitt, J., Sharkey, P., Tielsch, J.,
Legro, M.W., Kassalow, J., & Steinwachs, D., for the Cataract Patient Outcomes Research Team
(in press). Variation in ophthalmic testing prior to cataract surgery: Results of a national survey
of optometrists. Archives of Ophthalmology 113, 27-31.
Canner, J.K., Javitt, J.C., & McBean, A.M. (1992). National outcomes of cataract
extraction: III. Corneal edema and transplant following inpatient surgery. Archives of
Ophthalmology 110(8), 1137-1142.
Damiano, A.M., Steinberg, E.P., Cassard, S.D., Tielsch, J.M., Schein, O.D., Javitt, J., &
Kolb, M. (in press). Comparison of generic versus disease-specific measures of functional
impairment in patients with cataract. Medical Care.
Javitt, J.C. (1991). Outcomes of eye care from Medicare data [editorial]. Archives of
Ophthalmology 109(8), 1079-1080.
Javitt, J.C., Kendix, M., Tielsch, J.M., Steinwachs, D.M., Schein, O.D., Kolb, M.M.,
& Steinberg, E.P. (1995). Geographic variation in utilization of cataract surgery. Medical
Care 33(1), 90-105.
Javitt, J.C., Street, D.A., Tielsch, J.M., Wang, Q., Kolb, M.M., Schein, O., Sommer, A.,
Bergner, M., & Steinberg, E.P., on behalf of the Cataract Patient Outcomes Research
Team. (1994). National outcomes of cataract extraction: Retinal detachment and
endophthalmitis after outpatient cataract surgery. Ophthalmology 101(1),
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Javitt, J.C., Tielsch, J.M., Canner, J.K., Kolb, M.M., Sommer, A., & Steinberg, E.P., on
behalf of the Cataract Patient Outcomes Research Team. (1992). National outcomes of cataract
extraction: Increased risk of retinal complications associated with Nd:YAG laser capsulotomy.
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Javitt, J.C., Vitale, S., Canner, J.K., Krakauer, H., McBean, A.M., & Sommer, A. (1991).
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Javitt, J.C., Vitale, S., Canner, J.K., Street, D.A., Krakauer, H., McBean, A.M., & Sommer,
A. (1991). National outcomes of cataract extraction: Endophthalmitis following inpatient
surgery. Archives of Ophthalmology 109(8), 1085-1089.
Powe, N.R., Schein, O.D., Gieser, S.C., Tielsch, J.M., Luthra, R., Javitt, J., & Steinberg,
E.P., on behalf of the Cataract Patient Outcomes Research Team. (1994). Synthesis of the
literature on visual acuity and complications following cataract extraction with intraocular lens
implantation. Archives of Ophthalmology 112(2) 239-252.
Powe, N.R., Tielsch, J.M., Schein, O.D., Luthra, R., & Steinberg, E.P., on behalf of the
Cataract Patient Outcomes Research Team. (1994). Rigor of research methods in studies of the
effectiveness and safety of cataract extraction with intraocular lens implantation. Archives of
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Schein, O.D., Steinberg, E.P., Javitt, J.C., Cassard, S.D., Tielsch, J.M, Steinwachs, D.M.,
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Kolb, M., & Steinwachs, D. (1994). Variation in ophthalmic testing before cataract
surgery: Results of a national survey of ophthalmologists. Archives of Ophthalmology
112(7), 896-902.
Steinberg, E.P., Bergner, M., Sommer, A., Anderson, G.F., Bass, E.B., Canner, J.,
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Steinberg, E.P., Javitt, J.C., Sharkey, P.D., Zuckerman, A., Legro, M.W., Anderson, G.F.,
Bass, E.B., & O'Day, D. (1993). The content and cost of cataract surgery. Archives of
Ophthalmology 111(8), 1041-1049.
Steinberg, E.P., Tielsch, J.M., Schein, O.D., Javitt, J.C., Sharkey, P., Cassard, S.D.,
Legro, M.W., Diener-West, M., Bass, E.B., Damiano, A.M., Steinwachs, D.M., & Sommer, A.
(1994). National study of cataract surgery outcomes: Variation in 4-month postoperative
outcomes as reflected in multiple outcome measures. Ophthalmology 101(6),
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(1994). The VF-14: An index of functional impairment in patients with cataract. Archives
of Ophthalmology 112(5), 630-638.
Return to Cataract PORT Contents
Return to MEDTEP Update Contents