Geographic variation in drug safety: potentially unsafe prescribing of medications and prescriber responsiveness to safety alerts.

BACKGROUND Drug safety issues represent a major cause of morbidity and mortality. Alerting programs are intended to identify patients at potential risk for adverse drug reactions and may provide relevant information to prescribers to support their decision making about clinically appropriate risk reduction. Geographic differences in the incidence of drug safety issues and the responsiveness of prescribers to alerting systems have not been previously studied. OBJECTIVE To measure geographic differences in the rates of alerting events for potential drug safety issues, communicated to prescribers by mail or fax, and the responsiveness of prescribers to such alerts. METHODS All alerts generated by a commercially available drug safety alerting program were evaluated for calendar year 2008 and were classified geographically based on patient residence. Primary study measures were (a) number of alerting events per 1,000 members (i.e., covered beneficiaries of all ages whose plan sponsor was enrolled in the alerting program service), and (b) therapy change rate (defined as the percentage of alerts that were followed by therapy modification consistent with the clinical alert). RESULTS The program-wide aggregate rate of alerting events across all regions was 128 per 1,000 members, with the state-specific range from 78 to 240. The program-wide aggregate rate of drug therapy change across all regions was 54.0%, with the state-specific range from 48.1% to 59.5%. CONCLUSIONS The rates of potential drug safety issues (alerting events) and the responsiveness of prescribers to drug safety alerts vary considerably by region and state. States with high issue rates and low therapy change rates may require additional prescriber outreach.