Implications of county-level variation in U.S. opioid distribution.

Prescription opioids accounted for the majority of opioid-related deaths in the United States prior to 2010, and continue to contribute to opioid misuse and mortality. We used a novel dataset to investigate the distributional patterns of prescription opioids, whether opioid pill volume was associated with opioid-related mortality, and whether early state Medicaid expansions were associated with either pill volume or opioid-related mortality.