BACKGROUND: Models of health care coverage with varying degrees of patient cost-sharing have been shown to influence health care behaviors for chronic conditions including medication adherence. The effect of insurance cost-sharing subsidies on the probability of postoperative opioid refill, however, is unclear.
METHODS: This retrospective cohort study examined 100% Medicare claims data among patients (N = 21,781) ages 65 and older undergoing orthopedic procedures in Michigan between January 2013 and September 2016. Patients were classified based on the presence of low-income subsidy and on prior opioid exposure using Medicare Part D prescription files of drug events. We investigated the association of these factors with the probability of both initial and second postoperative opioid fill within 90 days from the date of discharge.
RESULTS: In this cohort, 84.6% of patients filled an initial opioid prescription, and 66.4% refilled an opioid prescription. Patients with a full low-income subsidy had greater odds of refill within the postoperative 90 days compared with those patients without a low-income subsidy (odds ratio 1.38, 95% confidence interval 1.18-1.60). Among opioid naïve patients with a full low-income subsidy, the adjusted refill rate was 61.3% (95% confidence interval 58.0-64.7%) compared with 57.6% (95% confidence interval 51.4-63.7%) among those with partial low-income subsidy and 54.2% (95% confidence interval 52.8-55.6%) among patients without low-income subsidy.
CONCLUSION: Among Medicare patients undergoing orthopedic procedures, a full medication subsidy is associated with an increased probability of opioid refill when compared with no subsidy. Going forward, it is critical to lessen financial barriers to ensure all patients have equitable access to postoperative analgesia, including both opioid and nonopioid analgesics by decreasing the patient burden of cost-sharing.