A Randomized Trial of Letters to Encourage Prescription Monitoring Program Use and Safe Opioid Prescribing

To facilitate safer prescribing of opioids and other drugs, nearly all states operate prescription monitoring programs (PMPs), which collect and share data on controlled substance dispensing. Policy makers have sought to raise clinicians' engagement with these programs but lack evidence on effective interventions. Working with the Minnesota Prescription Monitoring Program, we conducted a randomized trial to assess whether letters to clinicians increased program use and decreased risky coprescribing of opioids with benzodiazepines or gabapentinoids. In March 2021 we randomly assigned 12,000 coprescribers to either a control arm or one of three study arms sent differing letters. The respective letters highlighted a new mandate to check the PMP before prescribing, provided information about coprescribing risks with a list of coprescribed patients, or contained both messages combined. Letters highlighting the mandate alone or along with coprescribing information increased PMP search rates by 4.5 and 4.0 percentage points, respectively, with no significant effect on coprescribing. These letters also increased PMP account-holding rates among clinicians. Effects persisted for at least eight months. The letter with only coprescribing information had no detected effects on key outcomes. Our results support the use of simple letter interventions as evidence-based tools to increase PMP engagement and potentially facilitate better-informed prescribing.