Variations in postoperative opioid prescribing by day of week and duration of hospital stay

Background: Studies demonstrate wide variation in postoperative opioid prescribing and that patients are at risk of chronic opioid abuse after surgery. The factors that influence prescribing, however, remain obscure. This study investigates whether day of the week or the postoperative day at the time of discharge impacts prescribing patterns. Methods: We identified patients who underwent commonly performed procedures at our institution from January 2014 through April 2019 and analyzed the relationship between postoperative opioids prescribed (oral morphine milligram equivalents) and both the day of the week and the postoperative day at discharge. Results: In ambulatory operations (n = 13,545), each day progressing from Monday was associated with increased morphine milligram equivalents prescribed on discharge (P =.0080). For inpatient cases (n = 10,838), surgeons prescribed more morphine milligram equivalents at discharge in the latter half of the week and during the weekend (P =.0372). Every additional postoperative day at discharge was associated with a +19.25 morphine milligram equivalent prescribed (P <.0001). Conclusion: More opioids were prescribed on discharges later in the week and after prolonged hospital stays perhaps to avoid patients running out of medication. Providers may unintentionally allow such non-clinical factors to influence postoperative opioid prescribing. Increased awareness of these inadvertent biases may help decrease excess prescribing of potentially addicting opioids after an operation.