Mismatched opioid prescription in patients discharged after neurological surgeries: a retrospective cohort study.

Although postsurgical overprescription has been well-studied, postsurgical opioid underprescription remains largely overlooked. This retrospective cohort study was to investigate the extent of discharge opioid overprescription and underprescription in patients after neurological surgeries. Six thousand nine hundred forty-nine adult opioid-naive patients who underwent inpatient neurosurgical procedures at the University of California San Francisco were included. The primary outcome was the discrepancy between individual patient's prescribed daily oral morphine milligram equivalent (MME) at discharge and patient's own inpatient daily MME consumed within 24 hours of discharge. Analyses include Wilcoxon, Mann-Whitney, Kruskal-Wallis, and χ2 tests, and linear or multivariable logistic regression. 64.3% and 19.5% of patients were opioid overprescribed and underprescribed, respectively, with median prescribed daily MME 360% and 55.2% of median inpatient daily MME in opioid overprescribed and underprescribed patients, respectively. 54.6% of patients with no inpatient opioid the day before discharge were opioid overprescribed. Opioid underprescription dose-dependently increased the rate of opioid refill 1 to 30 days after discharge. From 2016 to 2019, the percentage of patients with opioid overprescription decreased by 24.8%, but the percentage of patients with opioid underprescription increased by 51.2%. Thus, the mismatched discharge opioid prescription in patients after neurological surgeries presented as both opioid overprescription and underprescription, with a dose-dependent increased rate of opioid refill 1 to 30 days after discharge in opioid underprescription. Although we are fighting against opioid overprescription to postsurgical patients, we should not ignore postsurgical opioid underprescription.