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

## TL;DR

A New York law capping opioid prescriptions after joint replacements led to a short-term reduction in opioid use compared to California.

## Contribution

The study provides evidence that state-level opioid cap laws can reduce immediate post-surgery opioid use in older adults.

## Key findings

- New York's opioid cap law was linked to a significant decrease in opioid fills in the first 7 days after surgery.
- The reduction was due to smaller prescription quantities and shorter prescription durations in New York compared to California.
- The law had no significant effect on opioid use beyond the first 7 days post-surgery.

## Abstract

This cohort study investigates whether a New York state law capping opioid prescribing was associated with a decrease in the quantity of opioids filled following total joint replacements among Medicare beneficiaries.

Was a 2016 opioid prescribing cap law in New York associated with changes in opioid prescribing for pain following total joint replacements (TJRs)?

In this cohort study of 31 028 Medicare beneficiaries, the New York law was associated with a decrease in total quantity of opioids filled in the immediate 7 days following TJRs in New York compared with California (control state). This reduction likely was attributable to decreases in quantity of opioids filled per prescription and duration of opioid prescriptions in New York compared with California.

The findings suggest that the New York opioid restriction law was associated with reductions in opioid quantities in the immediate TJR postoperative period.

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.

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

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.

Implementation of New York Section 3331 in July 2016.

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.

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.

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.