Practice patterns of the office-based ophthalmologist.

Practice patterns of office-based ophthalmologists were characterized using data collected from the National Ambulatory Medical Care Survey (NAMCS) of 1989, a national probability sample survey conducted by the National Center for Health Statistics. The sample includes office visits made between 1989 and 1990 to nonfederally-employed physicians primarily engaged in office-based practice. Over 38 million office-based patient visits documented in the NAMCS were analyzed. Fifty-two percent of patients (20.4 million) were over 65 years old; 90% (34.9 million) were white, with blacks and Asians accounting for 5% (1.9 million) and 3% (1.1 million) of visits, respectively. The leading primary diagnoses and professional activity associated with the visits were cataract/cataract surgery 23% (8.9 million), disorders of refraction 19.5% (7.5 million), and glaucoma 13% (4.9 million). Over 40% (16.1 million) of visits were for visual dysfunction, abnormal appearance, or abnormal sensation. Nearly 33% (12.5 million) were related to either a diagnostic/screening session or some form of treatment. The duration of visits ranged from 6 to 10 minutes (22.9%), 11 to 15 minutes (29.8%), and 31 minutes or longer (6.7%); 74% (28.1 million) of the patients were asked to return for a follow-up visit at a specified time, and 13% to return if needed. The major sources of reimbursement for office visits were Medicare (41%, 15.6 million); Blue Cross/Blue Shield (13%, 5 million); and other commercial insurance (15.5%, 5.8 million).