Limitations of AIDS reporting under favorable circumstances

To assess completeness of acquired immunodeficiency syndrome (AIDS) reporting by a consortium of Philadelphia physicians, we compared the consortium's patient data base to AIDS case reports received by the Philadelphia Department of Public Health (PDPH). Several circumstances favored better than ordinary reporting. Consortium physicians were highly motivated, specialized in the care of patients with human immunodeficiency virus disease, had worked with PDPH physicians for years, and knew beforehand about the plan to compare data bases. Of 295 patients in the consortium data base diagnosed with AIDS at least nine months prior to this study, 267 (90.5%) had been reported to the PDPH and 28 (9.5%) had not. Only two of the missed reports were deliberately withheld, each in response to the patient's request. Reporting completeness increased with the time elapsed since diagnosis, varied by practice from 70% to 100%, and was unrelated to patient demographic, insurance status, or occupational characteristics. AIDS reporting for patients in health care occupations (11/13 = 85% reported) was not significantly different from reporting for patients in other occupations (256/282 = 91% reported). We conclude that, under conditions favorable to reporting, approximately 10% of AIDS patients are not reported; the only patient characteristic that predicts reporting is the time elapsed since diagnosis; and nearly all reporting failures are inadvertent.