Opioid use in Older Orthopedic Rehabilitation Inpatients: A Retrospective Study

Background: While there is much evidence about pain management for orthopedic patients in the immediate perioperative setting, little is known about how opioids are used during inpatient rehabilitation in the days and weeks that follow, particularly in older adults. A safe upper limit of 50 oral morphine equivalents (OME) is frequently cited in guidelines. This study’s objective is to characterize the use of opioids in an older adult population undergoing orthopedic rehabilitation. Methods: This is a retrospective observational study of adults aged ≥50 years old admitted for orthopedic rehabilitation between November 2019 and June 2021 at an academic rehabilitation hospital in Toronto, Canada. Acute care admissions preceding rehabilitation were for either a surgical or non-surgical orthopedic indication. Participants were divided into opioid-naïve individuals who received opioids, opioid-naïve individuals who did not receive opioids, and pre-existing chronic users of opioids. Demographic, clinical, and medication administration data were collected through the electronic health record and manual chart review. Average daily opioid dose for the first seven days of each stay was characterized using OME. Linear regression was used to assess for variables independently associated with opioid dose. Results: A total of 643 patients undergoing orthopedic rehabilitation were included: 125 (19.4%) involved chronic opioid users, 416 (64.7%) were opioid-naïve patients who received opioids, and 102 (15.9%) were opioid-naïve patients who did not receive opioids, with median age respectively of 72, 79, and 83. Median daily OME over the first week for chronic users was 30.3 and for opioid-naïve users was 6.9. Opioid dose was significantly positively associated with reported pain as defined by day 3 pain score and knee replacement; it was inversely associated with admission for a non-surgical indication and age. Conclusions: Opioids are frequently but heterogeneously used in older adults undergoing orthopedic rehabilitation. Median OME use in this cohort of older adults was substantially lower than the 50 OME threshold suggested in guidelines. Dedicated guidance for opioid use is warranted for this unique patient population.