Dose Changes for Long-term Opioid Patients Following a State Opioid Prescribing Policy

In 2018, Nevada implemented opioid prescribing legislation (AB474) to support the uptake of CDC pain care guidelines. We studied the law's association with doses over threshold levels of morphine milligram equivalents (MMEs) and with time to dose increases and decreases, among long-term opioid patients.

A difference-in-difference study examined dosing changes across opioid prescription episodes (ie, prescriptions within 30 day and within the same dosing threshold). Patients with at least 120 days supply over 6 months in Nevada and Colorado Medicaid pharmacy claims were included. Using a logistic regression model, we compare the predicted probabilities that opioid episodes exceeded 50 MME before and after implementation of the law, in both states. Adjusted hazard ratios (aHR) from a gap time survival model estimated time to escalate above 50 MME among low-dose episodes (<50 MME), and time to de-escalate below 50 MME among high-dose episodes (≥50 MME).

Among 453,577 episodes (74,292 patients), the Nevada law was associated with a 2.9% reduction in prescriptions over 50 MME (95% CI: -3.5, -2.3) compared with Colorado. While the law was also associated with slower escalation (Nevada: aHR = 0.75; 95% CI: 0.72, 0.77, Colorado: aHR = 1.04; 95% CI: 1.01, 1.06), it was also associated with slower de-escalation (Nevada: aHR = 0.87; 95% CI: 0.84, 0.89, Colorado: aHR = 0.97; 95% CI: 0.96, 0.99).

Slower dose escalations, rather than faster dose de-escalation, likely explain post-law reductions in doses over 50 MME. Slower dose de-escalations may be due to longer days supply post-policy.