MARK-RECAPTURE ESTIMATES OF INJECTING DRUG-USERS IN SYDNEY

The number of injecting drug users in the Central and Eastern Sydney A rea Health Services (CSAHS and ESAHS) in 1989-1990 was estimated by ap plying the Petersen mark-recapture method to data obtained from the Au stralian National AIDS and Injecting Drug Use Surveys conducted in 198 9 and in 1990. The population estimates for injecting drug users were 8368 (95 per cent confidence interval (CI) 6099 to 11 829) for ESAHS a nd 1466 (CI 742 to 2841) for CSHS. An estimate was also obtained for t he number of injecting opioid users residing within the ESAHS; our fig ure of 3597 (CI 2731 to 5737) was consistent with previously reported estimates obtained using mark-recapture but based on different data se ts.