Incarceration and injection drug use in Baltimore, Maryland

Aims: There is limited longitudinal research examining incarceration and subsequent changes in drug use among people who inject drugs (PWID) in the United States. The objective of the current study was to characterize the frequency of incarceration and estimate the association between incarceration and subsequent injection drug use among current and former PWIDs in one US city. Design: ALIVE (AIDS Linked to the Intravenous Experience) is a prospective cohort study of current and former PWIDs, with semi-annual follow-up occurring since 1988. Setting: Baltimore, Maryland, USA. Participants: A total of 3245 participants with 48738 study visits were included. Participants enrolled from 1988 to 2012 with a median of 13 follow-up visits per participant (Interquartile range=7-25). Measurements: Incarcerations were defined as any self-reported jail or prison stays in the previous 6months that were ≥7days or longer. The primary outcome was defined as any self-reported injection drug use in the previous 6months. Findings: At baseline, 29% were female, 90% African American and 33% HIV-positive. Fifty-seven per cent of participants experienced at least one incarceration episode. After adjusting for confounders, there was a positive association between incarceration and subsequent injection drug use [adjusted odds ratio (AOR)=1.48, 95% confidence interval (CI)=1.37-1.59]; however, stratified analysis showed that the effect was restricted to those who were not injecting at the time of incarceration (AOR=2.11, 95% CI=1.88-2.37). Conclusions: In the United States, incarceration of people who had previously stopped injecting drugs appears to be associated with an increased risk of subsequent injecting.