Effectiveness of a Clinical Decision Support System for Reducing the Risk of QT Interval Prolongation in Hospitalized Patients

Background— We evaluated the effectiveness of a computer clinical decision support system (CDSS) for reducing the risk of QT interval prolongation in hospitalized patients. Methods and Results— We evaluated 2400 patients admitted to cardiac care units at an urban academic medical center. A CDSS incorporating a validated risk score for QT c prolongation was developed and implemented using information extracted from patients’ electronic medical records. When a drug associated with torsades de pointes was prescribed to a patient at moderate or high risk for QT c interval prolongation, a computer alert appeared on the screen to the pharmacist entering the order, who could then consult the prescriber on alternative therapies and implement more intensive monitoring. QT c interval prolongation was defined as QT c interval >500 ms or increase in QT c of ≥60 ms from baseline; for patients who presented with QT c >500 ms, QT c prolongation was defined solely as increase in QT c ≥60 ms from baseline. End points were assessed before (n=1200) and after (n=1200) implementation of the CDSS. CDSS implementation was independently associated with a reduced risk of QT c prolongation (adjusted odds ratio, 0.65; 95% confidence interval, 0.56–0.89; P <0.0001). Furthermore, CDSS implementation reduced the prescribing of noncardiac medications known to cause torsades de pointes, including fluoroquinolones and intravenous haloperidol (adjusted odds ratio, 0.79; 95% confidence interval, 0.63–0.91; P =0.03). Conclusions— A computer CDSS incorporating a validated risk score for QT c prolongation influences the prescribing of QT-prolonging drugs and reduces the risk of QT c interval prolongation in hospitalized patients with torsades de pointes risk factors.