Underreporting of AIDS, New South Wales, 1988-1989

To determine the completeness of medical practitioner reporting of patients with acquired immunodeficiency syndrome (AIDS) in New South Wales and the reasons for underreporting.

We compared the number of patients with AIDS reported to the National AIDS Register by medical practitioners from 1 July 1988 to 23 November 1989 with numbers detected from the National Zidovudine Register, AIDS specialist medical practitioner records, death certificates and the Sydney AIDS Prospective Study database. We asked the AIDS specialist medical practitioners to suggest why some patients may not be reported.

The number of persons known to have AIDS and the source from which they were detected.

We found 457 recorded cases of AIDS in which the diagnosis was made during the study period. Of these 457 cases, 373 (81.6%) had been reported by medical practitioners and 84 had not. Of these 84 cases, 40 were detected from the National Zidovudine Register, 24 from the records of AIDS specialist medical practitioners, 18 from death certificates and two from the Sydney AIDS Prospective Study. Reporting rates among hospitals ranged from 38.5% to 95.7%. We estimated that the true number of persons diagnosed with AIDS in New South Wales over the study period was 476. The main reasons given by the doctors for not reporting persons with AIDS were difficulties with reporting procedures and the complicated AIDS case definition, concerns about maintaining patient confidentiality and inadequate Health Department feedback on AIDS surveillance data.

At least 18.4% of the AIDS cases we detected were not reported by medical practitioners in New South Wales. More accurate information on the incidence of AIDS could be obtained if the Health Department regularly contacted AIDS specialist medical practitioners for unreported cases, simplified the reporting process, stressed the confidentiality provisions for AIDS reporting and provided feedback to reporting medical practitioners.