Stealth alerts increase monitoring of patients on warfarin

“Alert fatigue” diminishes the effectiveness of EHRs that warn physicians when they have prescribed a medication that interferes with another drug such as warfarin. Sending alerts to a patient management team rather than the prescribing physician increased the percentage of patients who were subsequently monitored, according to one study, suggesting that a “stealth” alert approach could be used to manage a variety of chronic diseases.

Patients with atrial fibrillation and other conditions often are prescribed the anticoagulant warfarin to reduce the risk of stroke or other adverse events. But warfarin interacts with other medications and food, which then can impede its anticoagulant effect. Physicians who use EHRs may receive an alert if they co-administer these drugs, but busy clinicians may not notice it or may not know what monitoring protocols to follow.

Kate E. Kaplan, MD, MPH, of Harvard Vanguard Medical Associates in Newton, Mass., and colleagues designed a study using their multispecialty medical group’s EHR system to test whether a stealth alert system would improve anticoagulation monitoring in patients whose physicians prescribed a medication that potentially interfered with warfarin. Rather than alert the prescribing physician, the EHR automatically sent an alert to a centralized Anticoagulation Management Service (AMS), which consisted of a team of nurses, pharmacists and physicians with anticoagulation expertise.

The researchers chose warfarin because it is a widely prescribed anticoagulant with a narrow therapeutic window. Co-administering other interacting drugs may be unavoidable at times; monitoring the patient’s international normalized ratio (INR) within the first five days helps to identify problems and minimize adverse effects.

The pre-post intervention study spanned 2008 and 2009 and included a 12-month pre-intervention period, a two-month implementation and a six-month post-intervention period. The primary outcome measure was the proportion of patients who completed INR monitoring within five days of having a new medication prescribed. Renewals and prescriptions for drugs that did not mediate warfarin’s anticoagulant effect did not trigger an alert. The study did not include dabigatran (Pradaxa, Boehringer Ingelheim), which was not available during the study period.

The pre- and post-intervention groups (1,553 patients and 1,709 patients, respectively) were similarly represented by sex and racial/ethnic group but the post-intervention group was slightly older and had a higher percentage of patients taking warfarin to treat atrial fibrillation (52.5 percent pre-intervention vs. 56.2 percent post-intervention).

A total of 34 percent of AMS patients completed INR monitoring within five days in the pre-intervention group compared with 39 percent in the post-intervention group. “The effect of this intervention was robust, with evidence of effectiveness in increasing monitoring rates as early as three days following the alert and as long as seven days following the alert,” Kaplan and colleagues wrote.

The stealth alert approach offered many benefits, they argued. It reduced alert fatigue among physicians and fostered sharing of responsibilities between the primary care and disease management groups. It facilitated the AMS for providing timely follow-up if clinically indicated. While their medical group used Epic's EHR, they wrote the system could be replicated in Epic or any EHR that meets Certification Commission for Health Information Technology standards.  

“The modest size of the intervention effect … should not diminish the potential value of this approach,” they wrote. For instance, medications covering a three-day period such as a short-acting antibiotic might be seen as low risk by the AMS and not needing monitoring. Others involved physicians entering a prescription as new when it was a refill. “Given these considerations, one would not necessarily expect 100 percent monitoring within five days of co-prescribing. In this context, an absolute 5 percent increase may appear more meaningful.”

The study did not measure outcomes or the time in therapeutic range, but the authors pointed out that increased INR monitoring would likely reduce the risk of complications. “Earlier monitoring in these situations fosters more frequent warfarin adjustments, and therefore likely maintenance of anticoagulation goal ranges, in addition to prevention of potential adverse effects of over-anticoagulation or under-anticoagulation.”

They concluded that the approach should be further tested as a way to reduce the burden of alert fatigue and to improve the quality of care in chronic disease management systems.

The study was published July 31 in the Journal of General Internal Medicine.