Overrides of medication alerts in ambulatory care.

Background: Electronic prescribing systems with decision support may improve patient safety in ambulatory care by offering drug allergy and drug interaction alerts. However, preliminary studies show that clinicians override most of these alerts.

Methods: We performed a retrospective analysis of 233 537 medication safety alerts generated by 2872 clinicians in Massachusetts, New Jersey, and Pennsylvania who used a common electronic prescribing system from January 1, 2006, through September 30, 2006. We used multivariate techniques to examine factors associated with alert acceptance.

Results: A total of 6.6% of electronic prescription attempts generated alerts. Clinicians accepted 9.2% of drug interaction alerts and 23.0% of allergy alerts. High-severity interactions accounted for most alerts (61.6%); clinicians accepted high-severity alerts slightly more often than moderate- or low-severity interaction alerts (10.4%, 7.3%, and 7.1%, respectively; P < .001). Clinicians accepted 2.2% to 43.1% of high-severity interaction alerts, depending on the classes of interacting medications. In multivariable analyses, we found no difference in alert acceptance among clinicians of different specialties (P = .16). Clinicians were less likely to accept a drug interaction alert if the patient had previously received the alerted medication (odds ratio, 0.03; 95% confidence interval, 0.03-0.03).

Conclusion: Clinicians override most medication alerts, suggesting that current medication safety alerts may be inadequate to protect patient safety.