Opioid use patterns following discharge from elective colorectal surgery: a prospective cohort study

Introduction: Opioid overprescription after colorectal surgery can lead to adverse events, persistent opioid use, and diversion of unused pills. This study aims to assess the extent to which opioids prescribed at discharge after elective colorectal surgery are consumed by patients.

Methods: This prospective cohort study included adult patients (≥ 18 yo) undergoing elective colorectal surgery at two academic hospitals in Montreal, Canada. Patients completed preoperative questionnaires and data concerning demographics, surgical details, and perioperative care characteristics (including discharge prescriptions) were extracted from electronic medical records. Self-reported opioid consumption was assessed weekly up to 1-month post-discharge. The total number of opioid pills prescribed and consumed after discharge were compared using the Wilcoxon signed-rank test. Negative binomial regression was used to identify predictors of opioid consumption.

Results: We analyzed 344 patients (58 ± 15 years, 47% female, 65% laparoscopic, 31% rectal resection, median hospital stay 3 days [IQR 1-5], 18% same-day discharge). Most patients received a TAP block (67%). Analgesia prescription at discharge included acetaminophen (92%), NSAIDs (38%), and opioids (92%). The quantity of opioids prescribed at discharge (median 13 pills [IQR 7-20]) was significantly higher than patient-reported consumption at one month (median 0 pills [IQR 0-7]) (p < 0.001). Overall, 51% of patients did not consume any opioids post-discharge, and 63% of the prescribed pills were not used. Increased opioid consumption was associated with younger age (IRR 0.99 [95%CI 0.98-0.99]), higher preoperative anxiety (1.02 [95%CI 1.00-1.04]), rectal resections (IRR 1.45 [95%CI 1.09-1.94]), and number of pills prescribed (1.02 [95%CI 1.01-1.03]).

Conclusion: A considerable number of opioid pills prescribed at discharge after elective colorectal surgery are left unused by patients. Certain patient and care characteristics were associated with increased opioid consumption. Our findings indicate that post-discharge analgesia with minimal or no opioids may be feasible and warrants further investigation.