Do opioid prescriptions lead to fatal car crashes?

Widespread opioid misuse suggests a potential for increased fatal car crashes. However, opioid use may not necessarily lead to additional crashes if drivers respond to opioid prevalence by substituting away from more inebriating intoxicants like alcohol. Combining data on local opioid prescription rates and car crashes from the Fatality Analysis and Reporting System, we use two-way fixed effects models to test the direction of the association between prescribing intensity and crash fatalities between 2007 and 2016. We estimate that a 10 percent increase in the local prescription rate is associated with a 1 percent increase in the number of driver deaths in motor vehicle accidents. The association is robust to several model specifications, and isolated to drivers most affected by the opioid crisis: males and 25 to 34 year-olds.