Effect of a patient-specific QTc alert on decreasing prescribing of QTc-prolonging medications in outpatients

Purpose Previous studies have shown decreased exposure to QTc-prolonging medications through utilization of a clinical decision support (CDS) alert in the electronic health record (EHR) in hospitalized patients. Minimization of risk factors, including exposure to QTc-prolonging medications, is important to decrease the risk of adverse outcomes, including ventricular arrhythmias. This study evaluated the effect of a patient-specific prolonged QTc EHR alert in nonhospitalized patients. Methods This was a single-center, retrospective, quasi-experimental pre-post analysis of an interruptive alert that is triggered in adult nonhospitalized patients upon entry of an order for a QTc-prolonging medication for patients with the following QTc criteria: (1) QTc of ≥500 ms or QTc of <550 ms with QRS of ≤130 ms without bundle branch block and not atrio-ventricular dual or ventricular paced or (2) QTc of >550 ms. Pre- and post-alert groups were compared for the primary outcome of the number of QTc-prolonging medication orders entered. Results The alert significantly decreased the number of orders for QTc-prolonging medications (odds ratio, 0.0017; 95% confidence interval, 0.0001-0.0281; P < 0.001). The alert override rate was 50%. No patients in either group had documentation of torsades de pointes. Conclusion This study demonstrated that an interruptive EHR alert at the time of order entry can decrease exposure to QTc-prolonging medications and potentially decrease the risk for ventricular arrhythmias in nonhospitalized patients with a prolonged QTc interval. Further research is needed to determine whether integration of other patient-specific parameters into the CDS alert would improve its potential to lower the risk of QTc-related adverse outcomes.