Pathways into Opioid Dependence: Evidence from Practice Variation in Emergency Departments

We use practice variation across physicians to uncover the role of medical care in causing opioid dependence. Using health records of 2 million US veterans with emergency department visits, we find that quasi-random assignment to a top (versus bottom) decile prescribing provider significantly increases subsequent opioid use and misuse rates. Instrumental variable results show that opioid prescription receipt leads to a 20 percent increase in …