Health Services/Policy
Using difference-in-difference analysis and decision trees to examine the efficacy of overdose prevention policies on opioid overdose mortality Chinelo Onyebeke* Chinelo Onyebeke John Pamplin
More than 500,000 people have died of opioid overdose in the US since 1999 and the number is still increasing per year. Rates of opioid overdose death are rising faster for Black people than any other racial/ethnic group, possibly due to reduced access to quality healthcare (including naloxone access), financial barriers, and mistrust of medical and other systems that are discriminatory and stigmatizing. Overdose prevention policies (i.e., Good Samaritan Laws and Naloxone Access Laws) are policy interventions enacted to reduce overdose mortality. Good Samaritan laws are state laws that provide legal protections for individuals who call 911 for the person experiencing the overdose. Naloxone access laws permit prescribing and dispensing of naloxone (i.e., Narcan, etc.) by health care providers and encourage its use by laypersons in a position to assist a person experiencing a drug overdose.
The goal of our study was to identify the set of harm reduction law provisions that provided the greatest reductions in opioid overdose mortality, both for the overall population and specifically among Black people. We generated difference-in-difference (DID) estimates of the effect of a policy enactment on overdose rates, as well as conducted a decision tree regression to show the predicted DID estimate based on which policy provisions were enacted.
In the preliminary decision tree results, the largest decrease in overdose deaths per 100,000 population was seen for Black individuals (including only enactments in which the parallel trends assumption was met for the DID analysis), where there was a predicted average decrease of 0.112 overdose deaths per 100,000 population when enactments contained the following policy provisions: “NAL Prescriber Immunity (civil)” and “NAL Prescriber Immunity (criminal)”. The findings of this study will aid in implementing sets of policies that best reduce opioid overdose rates for the overall population and Black individuals.