Cessation of injecting drug use: The effects of health service utilisation, drug use and demographic factors

Background: Injecting drug use is associated with a range of harms, however cessation of injecting is rare. There is a lack of evidence on factors associated with cessation, notably those related to health services other than drug treatment. We examined the incidence and identified longitudinal correlates of first episode of cessation in a cohort of people who inject drugs (PWID). Methods: Using discrete-time survival analysis, we examined correlates of the first episode of cessation (no self-reported injecting drug use in the past 12 months), including the use of health services, socio-demographics and drug-related behaviour in a cohort of PWID recruited between 2008 and 2010. Results: The cohort of 467 participants contributed 1527 person-years from recruitment to 2014. Under a fifth (17.8 ) of people reported cessation of 12 months or more, yielding a cessation rate of 5.4 events per 100 person-years. Younger age (25-29 compared to 30 and above) (adjusted hazard ratio (AHR) 1.79, 95 confidence interval (CI) 1.07-3.00) and male gender (AHR 1.67, 95 CI 2.01-2.76) were positively associated with cessation, while past year use of benzodiazepines (AHR 0.45, 95 CI 0.28-0.72), arrest in the past year (AHR 0.50, 95 CI 0.30-0.83) and low SF-8 physical dimension score (AHR 0.42, 95 CI 0.20-1.88) were negatively associated with cessation. Outpatient service use had the largest effect on cessation (AHR 2.28, 95 CI 0.94-5.48, p=. 0.067). Conclusions: Low rates of cessation emphasise the need for sustained and comprehensive harm reduction services. The relationship between outpatient services and cessation suggests that further research into the use in health services among PWID is warranted.