Reductions in non-medical prescription opioid use among adults in Ontario, Canada: are recent policy interventions working?

BACKGROUND: Non-medical prescription opioid use (NMPOU) and prescription opioid (PO) related harms have become major substance use and public health problems in North America, the region with the world’s highest PO use levels. In Ontario, Canada’s most populous province, NMPOU rates, PO-related treatment admissions and accidental mortality have risen sharply in recent years. A series of recent policy interventions from governmental and non-governmental entities to stem PO-related problems have been implemented since 2010. FINDINGS: We compared the prevalence of NMPOU in the Ontario general adult population (18 years+) in 2010 and 2011 based on data from the ‘Centre for Addiction and Mental Health (CAMH) Monitor’ (CM), a long-standing annual telephone interview-based representative population survey of substance use and health indicators. While ‘any PO use’ (in past year) changed non-significantly from 26.6% to 23.9% (Chi2 = 2.511; df = 1; p = 0.113), NMPOU decreased significantly from 7.7% to 4.0% (Chi2 = 14.786; df = 1; p < 0.001) between 2010 and 2011. Over-time changes varied by age group but not by sex. CONCLUSIONS: The observed substantial decrease in NMPOU in the Ontario adult population could be related to recent policy interventions, alongside extensive media reporting, focusing on NMPOU and PO-related harms, and may mean that these interventions have shown initial effects. However, other casual factors could have been involved. Thus, it is necessary to systematically examine whether the observed changes will be sustained, and whether other key PO-related harm indicators (e.g., treatment admissions, accidental mortality) change correspondingly in order to more systematically assess the impact of the policy measures.