Open Access

Introduction: Heroin overdose is a leading cause of mortality among drug users. This paper aims to identify individual and contextual factors associated with lethal and non-lethal heroin-related overdoses on the basis of case reports and semi-structured proxy interviews. Typical patterns within these cases are determined by means of cluster analysis. Methods: Within the CaRe (Case Reports of heroin-related overdoses) study, case reports (100 proxy reports of overdose events from 36 different facilities) were gathered and evaluated as part of a nationwide survey of experts conducted in Germany in 2019. Following initial descriptive analyses a two-step cluster analysis with the four binary variables of gender, age, time and place was conducted to identify patterns within the reported cases. Results: The case reports grouped into five clusters: 1) Younger male drug users, found in a public space during the daytime; 2) Female drug users; 3) Older male drug users, found in a public space during the daytime; 4) Drug users found at home at night; 5) Drug users found outside at night. Overdoses by female drug users and those which occurred at home and/or at night were significantly more likely to have a fatal outcome. Conclusion: Future prevention and intervention measures should aim to consider the context, i.e.