Opioid Cap Laws and Opioid Prescriptions After Total Joint Replacements in Older Adults.

Abstract

Importance: Despite the opioid crisis and a growing call for minimizing opioid use, opioids remain an important part of postoperative pain management, with more than 80% of patients filling at least 1 opioid prescription following total joint replacements (TJRs). Little is known as to whether state laws that restrict or cap opioids for acute pain reduce post-TJR opioid use.

Objective: To evaluate the association of an opioid cap law in New York (Section 3331) with post-TJR opioid prescribing.

Design, setting, and participants: This cohort study analyzed Medicare data from 2014 to 2019 for New York and California (control state). Participants were Medicare beneficiaries who underwent elective TJRs before (April 2014 to June 2016) or after (August 2016 to September 2019) Section 3331 implementation. Data were analyzed from June 2023 to August 2024.

Exposure: Implementation of New York Section 3331 in July 2016.

Main outcomes and measures: The primary end point was total morphine milligram equivalents (MMEs) filled from discharge to day 7, days 8 to 30, and days 31 to 90 after TJR. Key independent variables were legislation phase (before or after Section 3331 implementation), treatment or control state, and the interactions between these 2 variables. Difference-in-differences regression models were used to assess the association of interest.

Results: The pre-Section 3331 cohort included 32 253 TJR encounters among 31 028 patients, of whom 9924 (31.98%) underwent TJRs in New York hospitals. The mean (SD) age of the cohort was 73.43 (5.49) years; 19 442 encounters (60.28%) were among females. The estimated change in total MMEs filled in the 7-day post-TJR period after vs before Section 3331 implementation was -135.08 (95% CI, -146.62 to -123.53; P < .001) in California and -178.00 (95% CI, -191.98 to -164.02; P < .001) in New York, resulting in a Section 3331-associated change of -42.92 MMEs (95% CI, -61.04 to -24.80 MMEs; P < .001) in New York compared with California. Section 3331 was not associated with statistically significant changes in total MMEs filled in the 8 to 30-day and 31 to 90-day post-TJR periods.

Conclusions and relevance: The findings of this retrospective cohort study of TJRs among Medicare beneficiaries suggest that New York Section 3331 achieved its intended objective, as it was associated with reduced opioid fills in the immediate 7-day post-TJR period in New York compared with California. Additional refinements may further reduce opioid prescribing in New York, and these findings may serve as a foundation for refining laws in other states that may not achieve their intended targets or have not implemented similar laws.