Regional and temporal effects of naloxone access laws on opioid overdose mortality

Abstract

Background

Naloxone is a drug that reverses opioid overdose. Naloxone Access Laws (NALs) increase public access to naloxone and have been considered as one promising solution to reducing opioid-related harm. However, previous studies on whether NALs are effective in reducing opioid overdose mortality found somewhat contradictory results. Our study attempts to provide a more definitive answer to this question by utilizing an approach that matches NAL vs non-NAL states and stratifies by US region and years of implementation. Methods: We assess the causal impact of NALs on state-level opioid-related mortality rate by constructing a comparison group using matching to produce a valid counterfactual scenario, and estimating the effects of NAL using a semi-dynamic staggered difference in differences (DID) model that allows heterogeneous effects across regions and years of implementation. State-level opioid-related mortality data from CDC’s WONDER database and NALs effective from 1999 to 2014 were utilized. Results: We find that NAL effects have reduced fatal opioid-related overdose in western states and have produced minimal or no effects for other regions. Conclusions: The effects of NALs vary across regions and years of implementation. It is important to study the successful experience of the western states.

Keywords:

• Opioid
• naloxone access law
• difference in differences
• matching

Author contributions

Guido Cataife and Jing Dong participated in the research conception and design, collection of data, analysis, and the interpretation of the results. Corey Davis participated in the research design and the interpretation of the results. All authors participated in the writing of the manuscript.

Acknowledgements

We acknowledge the comments received during the presentation of this study at Academy Health 2019, especially those from Elizabeth Oliva.

Notes

1 https://wonder.cdc.gov/mcd.html

2 http://pdaps.org/datasets/laws-regulating-administration-of-naloxone-1501695139

3 https://www.kff.org/health-reform/state-indicator/state-activity-around-expanding-medicaid-under-the-affordable-care-act/?currentTimeframe=0&sortModel=%7B%22colId%22:%22Location%22,%22sort%22:%22asc%22%7D

4 http://pdaps.org/datasets/pdmp-implementation-dates

Additional information

Funding

The research time of Guido Cataife and Jing Dong was partially funded by IMPAQ International. The funding organization had no role in the design and conduct of the study; collection, management, analysis, and interpretation of the data; preparation, review, or approval of the manuscript; and decision to submit the manuscript for publication.