Exploration of the physical health of dual users of heroin and crack in methadone treatment who inject or have previously injected drugs

1.1 Background Heroin use in methadone treatment is more common for dual users of heroin and crack/cocaine, and intravenous use increases the risk of health complications. The aim of this study was to explore the physical health of intravenous drug users in methadone treatment with a focus on dual users. 1.2 Methods We analyzed the clinical records of 241 drug users with a history of injecting heroin and receiving methadone in two treatment services in London, UK, and conducted structured interviews with a subsample of 28 dual users. Statistical analyses included logistic regression and cluster analysis. 1.3 Results Poor health correlated positively with history of crack use, age, methadone dose, current injecting and negatively with age of first drug use. The prevalence of poor health was higher in those injecting both drugs compared to those smoking crack. Clustering analysis highlighted further possible determinants of health including reverse transition from injecting to smoking, high-risk injecting, cardiovascular risk. Higher methadone dose was not always associated with better health in dual users and individual factors played a relevant role in stopping injecting at a range of methadone doses. Client’s accounts on their experience of methadone treatment highlighted harm-reduction benefits of methadone beyond only abstinence. 1.4 Conclusions Our results suggest that dual users of heroin and crack are more likely to be in worse health compared to heroin-only users and that the physical health is multi-factorial. Services could capitalize on clients’ health beliefs as motivators towards safer practices or abstinence and focus more on health-related outcomes.