Experience of non-fatal overdose among heroin users in Adelaide, Australia: circumstances and risk perceptions

Aims. To ascertain the prevalence and risk factors for non-fatal overdose among heroin users to assist in the development of an effective intervention. Design. Cross-sectional design. Setting. Community setting, principally metropolitan Adelaide. Participants. Current heroin users (used heroin in the previous six months). Measurements. A structured questionnaire including the Severity of Dependence Scale. Finding. Of 218 current South Australian heroin users interviewed in 1996, 48% had experienced at least one non-fatal overdose their life-time (median: two overdoses), and 11% had overdosed in the previous 6 months. At some time, 70% had been present at someone else's overdose (median: three overdoses). At the time of their own most recent overdose, 52% had been using central nervous system depressants in addition to heroin, principally benzodiazepines (33%) and/or alcohol (22%). The majority of overdoses occurred in a private home (81%) and in the presence of other people (88%). Unrealistic optimism regarding the risk of overdose was evident across the sample. Despite almost half the sample reporting having had an overdose, and the belief expressed by respondents that on average about 50% of regular heroin users would overdose during their life-time 73% had, during the previous 6 months, "rarely" or "never" worried about possibly overdosing. Optimism regarding the possibility of future overdose was reduced in those with recent experience of overdose in comparison to the rest of the sample. A targeted intervention aimed at the reduction of overdose among heroin users is outlined.