Opioid Prescribing Among Hospitalized Patients in Tertiary Care Hospitals: A Retrospective Cohort Study

Background Over one in ten Canadians are prescribed an opioid annually. It is unknown if hospital prescribers are contributing to this high prescription rate. The purpose of this project was to describe opioid prescribing in two tertiary care hospitals in Canada. Methods This retrospective cohort study linked data from electronic discharge abstracts and inpatient prescription claims. Adult patients admitted to a medicine or surgery unit between January 2017 and December 2019 were eligible for inclusion. Opioid prescriptions were characterized by frequency, timing, duration, dosing, and route of administration. A random effects logistic regression model was built to identify independent predictors for an opioid prescription on day of discharge in patients with a medicine admission. Results A total of 38,218 patients were included (mean of 62 years, 52.2% female). Over half (57.7%) were admitted to a medicine unit, 26.8% to surgery, 8.5% trauma, and 7.0% other. Two-thirds of all hospital admissions (65.1%) received at least one opioid prescription (96.0% for surgery and 48.0% for medicine). Among these, 70.7% were prescribed an opioid with an as-needed interval only. On average, opioids prescriptions were active for 87.1% of the hospitalization, 96.8% were for strong potency agents, 67.8% for intravenous use, and 94.7% included a nonopioid analgesic prescription. On the day of discharge, 55.2% of all admissions had an active opioid prescription. After multivariable regression, the strongest predictors of receiving an opioid prescription on the day of discharge was duration of the opioid prescription during hospitalization and prescriptions for as-needed opioids only. Discussion We found high rates of opioid prescribing to patients in two Canadian hospitals, including on the day of discharge. A substantial number of patients are likely discharged with an opioid prescription. The patterns of opioid prescribing identified provide targets for strategies to reduce risks of unnecessary opioid exposure, such as individualizing analgesia and formulary restrictions. Future research should evaluate routine use of as-needed opioids, high potency agents, and duration of prescriptions