Tiering drug-drug interaction alerts by severity increases compliance rates.

Objective: Few data exist measuring the effect of differentiating drug-drug interaction (DDI) alerts in computerized provider order entry systems (CPOE) by level of severity ("tiering"). We sought to determine if rates of provider compliance with DDI alerts in the inpatient setting differed when a tiered presentation was implemented.

Design: We performed a retrospective analysis of alert log data on hospitalized patients at two academic medical centers during the period from 2/1/2004 through 2/1/2005. Both inpatient CPOE systems used the same DDI checking service, but one displayed alerts differentially by severity level (tiered presentation, including hard stops for the most severe alerts) while the other did not. Participants were adult inpatients who generated a DDI alert, and providers who wrote the orders. Alerts were presented during the order entry process, providing the clinician with the opportunity to change the patient's medication orders to avoid the interaction.

Measurements: Rate of compliance to alerts at a tiered site compared to a non-tiered site.

Results: We reviewed 71,350 alerts, of which 39,474 occurred at the non-tiered site and 31,876 at the tiered site. Compliance with DDI alerts was significantly higher at the site with tiered DDI alerts compared to the non-tiered site (29% vs. 10%, p < 0.001). At the tiered site, 100% of the most severe alerts were accepted, vs. only 34% at the non-tiered site; moderately severe alerts were also more likely to be accepted at the tiered site (29% vs. 10%).

Conclusion: Tiered alerting by severity was associated with higher compliance rates of DDI alerts in the inpatient setting, and lack of tiering was associated with a high override rate of more severe alerts.