Patterns of prescription opioid dispensing among Red River Métis in Manitoba, Canada: a retrospective longitudinal cross-sectional study

BACKGROUND: Amid rising concern about opioid use across Canada, Métis leaders in Manitoba are seeking information on prescription opioid dispensing in Red River Métis populations to assist with planning and implementing appropriate evidence-based harm-reduction strategies in their communities. We examined patterns of prescription opioid dispensing among Red River Métis and compared them to those among other residents of Manitoba. METHODS: We conducted a population-based retrospective cross-sectional study for fiscal years 2006/07–2018/19 using administrative data from the Manitoba Population Research Data Repository and a study designed in partnership with researchers from the Manitoba Métis Federation. We compared age- and sex-adjusted rates of prescription opioid dispensing and mean morphine equivalents (MEQ) between Red River Métis and all other Manitobans aged 10 years or older, in accordance with Indigenous data sovereignty principles. To better understand what was driving any differences in patterns of prescription opioid dispensing between the 2 groups, we stratified the groups by age, sex, urbanicity, number of comorbidities, income quintile and opioid type, and compared patterns in MEQ/person. RESULTS: The 2018/19 cohort included 76 755 Red River Métis and 1 117 854 other Manitobans. Other Manitobans were more likely than Red River Métis to be in higher income quintiles and to live in urban areas, and were less likely to have been diagnosed with a mood or anxiety disorder or a substance use disorder in the previous 5 years. The rate of prescription opioid dispensing and the opioid-associated MEQ/person were consistently higher among Red River Métis than among other Manitobans in each study year (p < 0.001). The rate of prescription opioid dispensing declined and the MEQ/person rose among other Manitobans over the study period but did not change among Red River Métis. INTERPRETATION: The rate of prescription opioid dispensing and the potency of prescribed opioids were higher among Red River Métis in Manitoba than among other Manitobans. Further investigation into the different dispensing patterns between the 2 groups and the potential opioid-related harms they may herald is warranted.