TY - JOUR
T1 - Impact of referral bias on evaluation of cataract surgery
AU - Kennedy, Robert H.
AU - Brubaker, Richard F.
AU - Michael O'Fallon, W.
AU - Joseph Melton, L.
N1 - Funding Information:
From the Departments of Ophthalmology (Drs. Kennedy and Brubaker) and Medical Statistics and Epidemiology (Drs. O'Fallon and Melton), Mayo Clinic and Mayo Foundation, Rochester, Minnesota. This study was supported in part by a grant from Research to Prevent Blindness, Inc. Presented at the annual meeting of the Association for Research in Vision and Ophthalmology, Sarasota, Florida, April 30, 1984.
PY - 1985/2/15
Y1 - 1985/2/15
N2 - Patients from a defined population (Olmsted County, Minnesota) who underwent cataract extraction during 1980 were compared with referral patients operated on at the Mayo Clinic to determine whether selective referral of patients introduces bias into studies conducted at academic centers. Rates of cataract extraction in Olmsted County increased continuously with increasing age and, in the older groups, were greater among females than males. The overall age- and sex-adjusted annual rate, 120 per 100,000 population, was considerably lower than that for 1980 in the United States, 209 per 100,000 population. A significantly greater proportion of referral patients had coexistent diabetes mellitus (P<.05) and underwent other ophthalmic surgical procedures in combination with cataract extraction (P<.001). Previous ophthalmic disorders were also more frequent among referral patients. Because selection for referral can distort data, this possible source of bias must be considered when interpreting data.
AB - Patients from a defined population (Olmsted County, Minnesota) who underwent cataract extraction during 1980 were compared with referral patients operated on at the Mayo Clinic to determine whether selective referral of patients introduces bias into studies conducted at academic centers. Rates of cataract extraction in Olmsted County increased continuously with increasing age and, in the older groups, were greater among females than males. The overall age- and sex-adjusted annual rate, 120 per 100,000 population, was considerably lower than that for 1980 in the United States, 209 per 100,000 population. A significantly greater proportion of referral patients had coexistent diabetes mellitus (P<.05) and underwent other ophthalmic surgical procedures in combination with cataract extraction (P<.001). Previous ophthalmic disorders were also more frequent among referral patients. Because selection for referral can distort data, this possible source of bias must be considered when interpreting data.
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U2 - 10.1016/0002-9394(85)90223-5
DO - 10.1016/0002-9394(85)90223-5
M3 - Article
C2 - 3970118
AN - SCOPUS:0021988361
SN - 0002-9394
VL - 99
SP - 149
EP - 153
JO - American journal of ophthalmology
JF - American journal of ophthalmology
IS - 2
ER -