"Stealth" alerts to improve warfarin monitoring when initiating interacting medications

J Gen Intern Med. 2012 Dec;27(12):1666-73. doi: 10.1007/s11606-012-2137-y. Epub 2012 Jul 31.


Background: As electronic health records (EHRs) become widely adopted, alerts and reminders can improve medication safety, but excessive alerts may irritate or overwhelm clinicians, thereby reducing their effectiveness. We developed a novel "stealth" alert in an EHR to improve anticoagulation monitoring for patients prescribed a medication that could interact with warfarin. Instead of alerting the prescribing provider, the system notified a multidisciplinary anticoagulation management service, so that the prescribing clinicians never saw the alerts. We aimed to determine whether these "stealth" alerts increased the frequency of anticoagulation monitoring following the co-prescription of warfarin and a potentially interacting medication.

Methods: We conducted a pre-post intervention study, analyzed using an interrupted time-series, within a large, multispecialty group practice that uses a common EHR. The study included a 12-month period preceding the intervention, a 2-month period during intervention implementation, and a 6-month post-intervention period. The primary outcome measure was the proportion of patients completing anticoagulation monitoring within 5 days of a new co-prescribing event.

Results: Prior to implementation of the stealth alert, 34 % of patients completed anticoagulation monitoring within 5 days after the prescription of a medication with a potential warfarin interaction. After implementation of the alert, 39 % completed testing within 5 days (odds ratio 1.24, 95 % confidence interval 1.12-1.37).

Conclusions: Stealth alerts increased the proportion of patients who underwent anticoagulation monitoring following the prescription of a medication that could potentially interact with warfarin. This team-based approach to clinical-decision support directs alerts away from prescribing clinicians and toward individuals who can directly implement them.

Publication types

  • Comparative Study
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Aged, 80 and over
  • Confidence Intervals
  • Cross-Sectional Studies
  • Drug Interactions
  • Drug Monitoring / methods*
  • Drug Therapy, Combination
  • Drug-Related Side Effects and Adverse Reactions / prevention & control*
  • Female
  • Humans
  • Male
  • Medical Order Entry Systems*
  • Middle Aged
  • Odds Ratio
  • Practice Patterns, Physicians' / trends
  • Quality Improvement
  • United States
  • Warfarin / administration & dosage*
  • Warfarin / adverse effects
  • Young Adult


  • Warfarin