Trends in opioid use before critical illness among elderly patients in Ontario.

Purpose: To assess temporal trends in pre-existing opioid exposure prior to hospitalization among elderly intensive care unit (ICU) patients and its association with adverse outcomes.

Materials And Methods: We performed a population-based retrospective cohort study using health administrative data from the province of Ontario, Canada. We included all older adult (> 65 years) admissions to an ICU between April 2002 and March 2015. The exposure was opioid use before admission categorized as chronic use, intermittent use, and non-use.

Results: The cohort included 711,312 elderly patient admissions to an ICU. Of these, 6.8% (n = 48,363) were chronic opioid users, 28.1% (n = 200,149) intermittent users, and 65.0% (n = 462,800) non-users. Compared with non-users, chronic opioid users and intermittent users had higher in-hospital mortality (adjusted odds ratio: 1.12, 95% CI, 1.09-1.15, p < 0.0001 for chronic users; adjusted odds ratio: 1.09, 95% CI, 1.07-1.11, p < 0.0001 for intermittent users), and a lower subdistribution hazard of time to hospital discharge, translating to a longer hospital length of stay (adjusted hazard ratio: 0.87, 95% CI, 0.85-0.88, p < 0.0001 for chronic users; adjusted hazard ratio: 0.93, 95% CI, 0.92-0.94, p < 0.0001 for intermittent users).

Conclusions: Among elderly ICU patients, opioid exposure prior to admission is prevalent and use is associated with higher in-hospital mortality.