Opioid prescribing practices in breast oncologic surgery-A retrospective cohort study.

Background: In breast oncologic surgery, 75% of patients receive a postoperative opioid prescription at discharge, and 10%-20% will develop persistent opioid use. To inform future institutional guidelines, the objective of this study was to determine baseline opioid prescribing patterns in a single high-volume, referral-based breast center. We hypothesized that opioid prescribing practices varied between procedures and operating surgeons.

Methods: A retrospective analysis of all women undergoing breast cancer surgery between January and December 2019. Opioid prescriptions at discharge were converted to morphine milligram equivalents (MME). The primary outcome of interest was MME prescribed at discharge. Multiple linear regression was used to identify factors independently associated with MME prescribed.

Results: 392 patients met inclusion criteria; 68.3% underwent partial mastectomy. Median age was 61 (interquartile range [IQR] 51-70). Median MME prescribed at discharge was 112.5 (IQR 75-150); 83.9% of patients were prescribed co-analgesia. The prescriber was a trainee in 37.7% of cases. 15 patients (3.8%) required opioid renewal. On multivariate analysis, axillary procedure was associated with increased MME (ß = 17, 95% CI 5.5-28 and ß = 32, 95% CI 17-47, for sentinel node and axillary dissection, respectively). However, the factor with the greatest impact on MME was operating surgeon (ß = 72, 95% CI 58-87). Residents prescribed less MME compared to attending surgeons (ß = 11, 95% CI -22; -0.06).

Conclusion: In a tertiary care center, the operating surgeon had the greatest influence on opioid prescribing practices, and trainees tended to prescribe less MME. These findings support the need for a standardized approach to optimize prescribing and reduce opioid-related harms after oncologic breast surgery.