Chronic Opioid Therapy Utilization Following an Acute Pain Prescription Supply Restriction Law: An Interrupted Time Series Analysis.

Background: Florida House Bill 21 (HB21) was implemented in July 2018 to limit Schedule II opioids prescriptions for patients with acute pain to a 3-day supply. Little is known about the potential unintended effects that such opioid restriction policies may have on chronic pain patients, who are exempt from the law.

Objective: We aimed to evaluate the effect of HB21 on opioid utilization measures among a cohort of chronic opioid therapy (COT) patients.

Study Design: A quasi-experimental design with interrupted time series analyses.

Setting: Pharmacy claims from January 1, 2015 to June 31, 2019 from a large employer-based health plan in Florida.

Methods: COT patients were those who received a ≥ 70 days' supply of opioids in the prior 90 days, representing 15,310 patients. Interrupted time series analyses were conducted to compare the following monthly measures among COT patients before and after HB21 implementation: 1) number of COT patients, 2) daily Morphine Milligram Equivalents [MMEs], 3) days' supply of prescriptions.

Results: There was a significant 25% reduction in the trend (pre-HB21 RR: 0.95, 95% CI: 0.93, 0.96 versus post-HB21 RR: 0.70, 95% CI: 0.65, 0.76) and an 8% immediate decrease (RR: 0.92, 95% CI: 0.88, 0.97) in the monthly prevalence of COT patients after HB21 implementation. However, no significant change was observed in trends for monthly number of days supplied per prescription, monthly MMEs per COT patient-day, or total MMEs per prescription.

Limitations: Our study used data from employer-based private health insurance and did not include a longer post-policy period to adjust for implementation lag.

Conclusion: Fewer patients received COT after HB21; however, patients who continued to receive COT experienced no significant changes in their regimen. The study did not assess whether COT patients were appropriately tapered or if therapeutic alternatives were initiated for new chronic pain patients.