Restricted needle and syringe program (NSP) operating hours in Australia have been reported as a barrier to access for people who inject drugs (PWID). We explored the prevalence of drug use occurring outside NSP operating hours with a particular focus on its impacts on individual-level needle and syringe coverage.

Using data from 584 participants in a cohort of PWID in Melbourne, Australia, we analyzed time and day of drug use for heroin, methamphetamine and pharmaceutical opioids. We related this drug use to the typical operating times of Melbourne's fixed-site NSPs, categorizing drug use as either "in-hours" or "out-of-hours". We explored associations with out-of-hours drug use using a generalized linear mixed model of pooled longitudinal data.

23% of heroin use and 50% of methamphetamine use occurred out-of-hours. In regression analysis, males and those injecting in public locations had significantly reduced odds of out-of-hours drug use. Those currently employed and those using methamphetamine (compared to heroin) had significantly increased odds of out-of-hours drug use. There was no significant association between individual-level needle and syringe coverage and hours of drug use.

Deficiencies in individual-level needle and syringe coverage may not be due to restricted NSP operating hours. Instead, insufficient coverage may be the result of other factors in the lives of PWID or other NSP access difficulties. These preliminary results suggest improvements to coverage in Australia may not result from increased hours of NSP operation, but instead via improvements to client targeting.