Prescription opioid policies and associations with opioid overdose and related adverse effects

Background: United States (US) policies to mitigate the opioid epidemic focus on reducing access to prescription opioids to prevent overdoses. We examined the impact of state policies in Vermont (July 2017) and Maine (July 2016) on opioid overdoses and opioid-related adverse effects. Methods: Study population included patients 15 years and older in all-payer claims of Vermont ( N = 597,683; Jan.2016-Dec.2018) and Maine ( N = 1,370,960; Oct.2015-Dec.2017). We used interrupted time series analyses to assess the impact of opioid prescribing policies on monthly opioid overdose rate and opioid-related adverse effects rate. We used the International Classification of Disease-10-CM to identify overdoses (T40.0 x 1-T40.4 x 4, T40.601-T40.604, T40.691-T40.694) and adverse effects (T40.0 x 5, T40.2 x 5-T40.4 x 5, T40.605, T40.695). Results: Immediately after the policy, the level of Vermont's opioid overdose rate increased by 34% (95% confi-dence interval, CI: 1.09, 1.65) while the level of opioid-related adverse effects rate decreased by 29% (95% CI: 0.58, 0.87). In Maine, there was no level change in opioid overdose rate, but the slope of the adverse effects rate after the policy decreased by 3.5% (95% CI: 0.94, 0.99). These results varied within age and rurality subgroups in both states. Conclusion: While the decrease in rate of adverse effects following the policy changes is promising, the increase in Vermont's opioid overdose rate may suggest there is an association between policy implementation and short -term risk to public health.