Content Validation of an Algorithm for the Assessment, Management and Monitoring of Drug-Induced QTc Prolongation in the Psychiatric Population

Abstract

Background: QTc interval prolongation leads to serious complications, making it a concern for clinicians. Assessing the risk of QTc interval prolongation in the psychiatric population is important, as they are exposed to medications known to increase the risk of life-threatening arrhythmias. Aim: To validate the content of an algorithm for the assessment, management and monitoring of drug-induced QTc prolongation in the psychiatric population. Methodology: Qualitative semi-structured interviews of cardiology experts were used to gather information on their approach in assessing the risk of drug-induced QTc prolongation at the time of prescribing. After the interview, an orientation to the algorithm was provided, followed by a self-administered survey which included quantitative (4-point Likert scale to rate their opinion on each decision step) and qualitative components to assess the algorithm's content validity. Results: Four themes emerged from the cardiologists' interviews, which pointed towards a lack of a unified protocol or a systematic approach when assessing QTc interval prolongation. Quantitative results showed average mean scores ranging from 3.08 to 3.67, 3.08 to 3.58, and 3.17 to 3.75, for the appropriateness; the safety; and the reliability of the references, respectively, of each decision step in the algorithm. Qualitative analysis of the open-ended questions showed that cardiologists supported implementing the algorithm, with slight modifications to make it simpler and less time consuming. Conclusion: Qualitative and quantitative results point towards positive indices for the algorithm's content validity. Further validation studies with other potential users of the algorithm (such as mental health practitioners) are needed.