Laboratories of Harm Reduction and Treatment: Determinants of States' Policy Adoptions to Address the Opioid Epidemic

Context: In the U.S. federal system, states have adopted a wide array of opioid-related policies over the past thirty years to address the ongoing overdose crisis. The underlying factors driving this variation remain unclear. Understanding what influences states to adopt more comprehensive policies—and whether they prioritize harm reduction or opioid use disorder (OUD) treatment—has important implications for public health strategy and policymaking. Methods: This study develops state-level indexes using dozens of policy indicators to measure the comprehensiveness of opioid-related policies across two dimensions: harm reduction and treatment. Feature rank analysis and multilevel mixed effects regression are employed to assess the influence of various political, epidemiological, and socioeconomic factors. Findings: We find that decreases in conservative citizen ideology, increases in the severity of the overdose crisis, and increases in states' economic resources are the most consistent factors influencing adoptions of more comprehensive policies. These factors shaped not only the overall robustness of state responses but also the emphasis on specific policy dimensions. Conclusions: The study highlights key drivers behind the variation in state-level opioid policy comprehensiveness, offering a clearer picture of how political and contextual factors influence public health policymaking. These insights can guide future research on state-level health policy adoption.