title: Confirmation of self-reported cataract in the Physicians' Health Study.
abstract: Large-scale prospective studies of disease development often rely on self-reported data. To assess the accuracy of self-reports of cataract, we compared the self-reports with medical record data obtained from diagnosing ophthalmologists and optometrists for participants in the Physicians' Health Study, a randomized trial of aspirin and beta-carotene among 22,071 male U.S. physicians aged 40-84 years. A report of cataract, defined as a positive response to a question about whether cataract had ever been diagnosed in either eye and the date of diagnosis, was found to be a very good indicator of lens opacification but was not a good indicator of an incident, age-related opacity that reduced visual acuity. These results indicate that in large prospective studies of clinically significant cataract, where examination of all study participants is not feasible and self-reported data are used, additional documentation to supplement the self-reports should be obtained and strict diagnostic criteria applied to minimize the likely effects of misclassification.
authors.affiliation: Department of Medicine, Harvard Medical School, Boston, Massachusetts, USA.
authors.forename: W G
authors.initials: WG
authors.lastname: Christen
authors.forename: R J
authors.initials: RJ
authors.lastname: Glynn
authors.forename: J M
authors.initials: JM
authors.lastname: Seddon
authors.forename: J E
authors.initials: JE
authors.lastname: Manson
authors.forename: J E
authors.initials: JE
authors.lastname: Buring
authors.forename: C H
authors.initials: CH
authors.lastname: Hennekens
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000975:Antioxidants / Q000627:therapeutic use; D001241:Aspirin / Q000627:therapeutic use; D002318:Cardiovascular Diseases / Q000517:prevention & control; D002338:Carotenoids / Q000627:therapeutic use; D002386:Cataract / Q000175:diagnosis* / Q000453:epidemiology* / Q000209:etiology; D004311:Double-Blind Method; D005500:Follow-Up Studies; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D010820:Physicians; D010975:Platelet Aggregation Inhibitors / Q000627:therapeutic use; D016032:Randomized Controlled Trials as Topic; D015203:Reproducibility of Results; D012189:Retrospective Studies; D012650:Self Disclosure; D014481:United States / Q000453:epidemiology; D014792:Visual Acuity; D019207:beta Carotene
chemical_list: D000975:Antioxidants; D010975:Platelet Aggregation Inhibitors; D019207:beta Carotene; D002338:Carotenoids; D001241:Aspirin