Differences by Sex in Perioperative Opioid Prescription Patterns for Outpatient Total Knee Arthroplasty.

Introduction: Sex-based differences in opioid prescribing following total knee arthroplasty (TKA) have been reported, though little is known about outpatient TKA or older adults. This study examined sex differences in perioperative opioid prescribing patterns among patients undergoing outpatient TKA.

Methods: This retrospective cohort study utilized 2018 to 2021 data from a national database (ages 18 to 64 years) and the Medicare Supplemental (ages 65 plus years) database. We identified patients undergoing outpatient primary TKA and examined perioperative opioid prescription fills, oral morphine milligram equivalents (MMEs) prescribed, and subacute and persistent opioid use. Multivariable regression models examined the association between sex (men versus women) and outcomes, adjusting for covariates, separately in the commercial and Medicare cohorts.

Results: In the commercial cohort (n = 21,788; 43.6% men), there was no association between sex and filling a perioperative opioid prescription, but men had higher perioperative MMEs (22.5, 95% confidence interval (CI): 12.30 to 32.79, P < 0.001) and lower odds of subacute (odds ratio (OR) = 0.77, 95% CI: 0.71 to 0.83, P < 0.001) and persistent (OR = 0.84, 95% CI: 0.76 to 0.94, P = 0.002) opioid use compared to women. In the Medicare cohort (n = 7,518; 37.6% men), men had increased odds of filling a perioperative opioid prescription (OR = 1.18, 95% CI: 1.03 to 1.36, P = 0.02) and higher perioperative MMEs (19.45, 95% CI: 0.60 to 38.29, P = 0.04), as well as lower odds of subacute opioid use (OR = 0.80, 95% CI: 0.68 to 0.93, P = 0.005).

Conclusions: Following outpatient TKA, men were prescribed higher perioperative opioid doses, but were less likely to continue opioids postoperatively. Future research is needed to understand the mechanisms and appropriateness of these observed differences, particularly for women who may be at higher risk for continued postoperative opioid use.