The prevalence and predictors of discharge opioid overprescribing in opioid-naïve patients after breast, gynecologic, and head and neck cancer surgery: a prospective cohort study.

Purpose: The management of pain following cancer-related surgeries involves the use of opioid analgesics. Nevertheless, there is little evidence characterizing the utility and prescription patterns of opioids after these procedures. Our primary aim was to identify patients from three types of cancer surgery who were overprescribed with opioids. The secondary aim was to determine the potential predictors of overprescribing in the same period.

Methods: We conducted the study at a single cancer referral hospital. Opioid-naïve patients with breast, gynecologic, or head and neck cancer were studied. Patients were considered opioid-naïve if they had a history of opioid use ≤ 30 mg oral morphine equivalent daily dose for less than seven days in the preceding three months before surgery. We recruited eligible participants by convenience sampling on the wards until at least 102 patients were included in the final analysis. After discharge, we followed up on the participants on day 7 via telephone using a structured proforma including questions to identify the last date and amount of opioid dose taken. The equivalent days of opioid use were calculated by their 24-hr use before discharge and the number of doses prescribed for discharge. Our primary outcome was the prevalence of overprescribing in the three surgical specialties defined as the number of patients taking less than 50% of discharge opioids within the first seven days after discharge. We examined the predictors on incidents of overprescribing using multivariable Poisson regression as the secondary outcome.

Results: We recruited 119 patients, and 107 patients were included in the final analysis. There were 59/107 (55%) patients found to be overprescribed with opioids. At discharge, they exhibited lower mean numerical rating scale pain scores, lower mean pain severity scores, higher equivalent days of opioids prescribed, and not used opioids in the last 24 hr before discharge. The incidence of overprescribing was 2.4 times greater for patients prescribed with opioids without 24-hr opioid use (relative risk [RR], 2.38; 95% confidence interval [CI], 1.30 to 4.35; P = 0.005). Similarly, the incidence of overprescribing was 1.7 times greater for patients who had opioids 24 hr before discharge and were supplied with opioids for five equivalent days or more at the time of discharge (RR, 1.67; 95% CI, 1.09 to 2.56; P = 0.02).

Conclusion: Our study shows that the majority of recruited patients undergoing breast, gynecologic, or head and neck cancer surgery were overprescribed opioids. Individualized assessments on patients' 24-hr opioid requirements before discharge and supplying for less than five days are important considerations to reduce overprescribing in opioid-naïve patients after cancer surgery.