Greater opioid use among nursing home residents in Ontario, Canada during the first two waves of the COVID-19 pandemic

Objectives — To examine the association between the COVID-19 pandemic and opioid use among nursing home residents followed up to March 2021, and possible variation by dementia and frailty status.

Design — Population-based cohort study with an interrupted time series analysis.

Setting and Participants — Linked health administrative databases for residents of all nursing homes (N=630) in Ontario, Canada were examined. Residents were divided into consecutive weekly cohorts (first observation week was March 5 to 11, 2017 and last was March 21 to March 27, 2021).

Methods — The weekly proportion of residents dispensed an opioid was examined overall and by strata defined by the presence of dementia and frailty. Autoregressive Integrated Moving Average (ARIMA) models with step and ramp intervention functions tested for immediate level and slope changes in weekly opioid use after the onset of the pandemic (March 1, 2020) and were fit on pre-pandemic data for projected trends.

Results — The average weekly cohort ranged from 76,834 residents (pre-pandemic) to 69,359 (pandemic period), with a consistent distribution by sex (69% female) and age (54% aged 85+ years). There was a statistically significant increased slope change in the weekly proportion of residents dispensed opioids (parameter estimate [β]=0.035; standard error [SE]=0.005, p<0.001). While significant for all four strata, the increased slope change was more pronounced among non-frail residents (β=0.038; SE=0.008, p<0.001) and those without dementia (β=0.044; SE=0.008, p<0.001). The absolute difference in observed vs predicted opioid use in the last week of the pandemic period ranged from 1.25% (frail residents) to 2.28% (residents without dementia).

Conclusions and Implications — Among Ontario nursing home residents, there was a statistically significant increase in opioid dispensations following the onset of the pandemic that persisted up to one year later. Investigations of the reasons for increased use, potential for long-term use and associated health consequences for residents are warranted.