Timing of income assistance payment and overdose patterns at a Canadian supervised injection facility
Maria Zlotorzynska, M.-J.S. Milloy, Lindsey Richardson, Paul Nguyen, Julio S. Montaner, Evan Wood, Thomas Kerr
International Journal of Drug Policy
4 April 2014
•Overdose risk at Insite increased on days after social assistance cheques issued.
•Increased overdose risk observed when drug-specific rates were considered.
•Proportion of overdoses involving opioids decreased on days after cheque issuance.
•Increased overdose risk may be associated with higher-risk drug behaviour.
Little is known about the relationship between timing of income assistance provision and health behaviours among injection drug users (IDU). We therefore investigated associations between income assistance provision and overdose patterns among IDU utilizing Insite, a supervised injection facility in Vancouver, Canada.
Using data collected at Insite between March 2004 and December 2010, we examined trends in overdoses and drugs injected. Data were stratified by proximity to the most recent day of issue of income assistance cheques, based on dates provided by the province.
After adjustment for frequency of use, the risk of overdose for those injecting at Insite on the three days starting with “cheque day” was higher than for those injecting on other days (Odds Ratio [OR] = 2.06; 95% Confidence Interval [CI]: 1.80–2.36, p < 0.001). These associations were also significant when drug-specific overdose rates were considered. The proportion of overdoses involving exclusive opioid use was lower for events occurring around cheque day than on other days (OR = 0.63; 95% CI: 0.47–0.84, p = 0.002), though we observed no significant association between the proportion of overdoses involving stimulants and cheque timing (p = 0.129).
The risk of overdose among IDU utilizing Insite was significantly higher on and immediately after cheque day than during other days, and may be associated with reduced tolerance and increases in binge drug use. Alternative models of income assistance administration should be evaluated to reduce overdoses around cheque day.