The effect of neighborhood deprivation and residential relocation on long-term injection cessation among injection drug users (IDUs) in Baltimore, Maryland

Aims To determine the incidence of long-term injection cessation and its association with residential relocation and neighborhood deprivation. Design ALIVE (AIDS Linked to the Intravenous Experience) is a prospective cohort with semi-annual follow-up since 1988. Multi-level discrete time-to-event models were constructed to investigate individual and neighborhood-level predictors of long-term injection cessation. Setting Baltimore, USA. Participants A total of 1697 active injectors from ALIVE with at least eight semi-annual study visits. Measurements Long-term injection cessation was defined as 3 consecutive years without self-reported injection drug use. Findings A total of 706 (42%) injectors achieved long-term cessation (incidence=7.6 per 100 person-years). After adjusting for individual-level factors, long-term injection cessation was 29% less likely in neighborhoods in the third quartile of deprivation [hazard ratio (HR)=0.71, 95% CI: 0.53, 0.95) and 43% less likely in the highest quartile of deprivation (HR=0.57, 95% CI: 0.43, 0.76) compared to the first quartile. Residential relocation was associated with increased likelihood of long-term injection cessation (HR=1.55, 95% CI: 1.31, 1.82); however, the impact of relocation varied depending on the deprivation in the destination neighborhood. Compared to those who stayed in less deprived neighborhoods, relocation from highly deprived to less deprived neighborhoods had the strongest positive impact on long-term injection cessation (HR=1.96, 95% CI: 1.50, 2.57), while staying in the most deprived neighborhoods was detrimental (HR=0.76, 95% CI: 0.63, 0.93). Conclusions Long-term cessation of injection of opiates and cocaine occurred frequently following a median of 9 years of injection and contextual factors appear to be important. Our findings suggest that improvements in the socio-economic environment may improve the effectiveness of cessation programs.