Impact of binge alcohol on mortality among people who inject drugs

• The impact of poly-substance use with alcohol on mortality is not well-described in the literature.
• Binge alcohol use was examined in two prospective cohort studies in Vancouver, Canada.
• We examined all-cause mortality for people who inject drugs (PWID).
• In this setting, binge alcohol use is positively and independently associated with all-cause mortality.

IntroductionWhile the impacts of illicit drug use on mortality have been well described, the impact of poly-substance that includes alcohol has received less attention. We examined the impact of binge alcohol use on mortality among a cohort of people who inject drugs (PWID) in a Canadian setting.MethodsUsing data derived from a prospective cohort study of PWID in Vancouver, Canada recruited between May 1996 and November 2013. We ascertained dates and causes of death through a confidential linkage with the provincial registry and examined the impact of binge alcohol use. The primary outcome of interest was all-cause mortality. We used Cox proportional hazard regression to determine factors associated with mortality, including socio-demographic characteristics, drug use patterns and other risk behaviours.ResultsDuring the study period, 2550 individuals were followed (844 of whom were HIV positive at baseline) for a median of 75.4 months (interquartile range 37.9–113.2). Of these, 795 (31%) participants reported binge alcohol use at some time during the study period. In multivariable analyses, binge alcohol use remained independently associated with all-cause-mortality (adjusted hazard ratio = 1.41; 95% confidence interval: 1.06–1.88) after adjustment for other drug use patterns.ConclusionsBinge alcohol use was associated with time to all-cause mortality among PWID in this setting. Since alcohol use is often overlooked as a risk factor for mortality among this population, these findings highlight the continued need to incorporate addiction treatment and public health interventions and policies that address binge alcohol use to reduce alcohol related-harms.