Table 3.

QT prolongation risk assessment tools

Tool	Description
Tisdale risk score for QT prolongation (www.mdcalc.com/tisdale-risk-score-qt-prolongation) 16	Predicts the risk of QT prolongation >500 ms in hospitalised patients. Uses risk factors that are weighted. Suitable for patients in CCCUs. A score ≥11 predicted development of a QT interval >500 ms. The tool was developed using patients admitted to CCCUs and hence generalisability to broader populations may be limited.
MedSafety Scan (MSS) QT prolongation risk score (https://medsafetyscan.org/)	A platform for therapeutic decision support that incorporates the QT drugs database from the CredibleMeds website with reliable drug–drug interaction predictions to identify patients at greatest risk of major adverse drug reactions. Built to deliver accurate therapeutic risk assessment without false positives or irrelevant information. Calculation of QT risk score for ICU patients based on Tisdale risk score (validated), or for non-ICU patients using the MSS QT prolongation risk score (non-validated). It includes the risk factors in the Tisdale tool and additional risk factors reported in the literature, such as drug interactions and other validated cardiac risk factors. It is more comprehensive than the Tisdale tool. Provides advice on drug interactions.
Risk of QT drug–drug interactions assessment tool. 34	A tool enabling the identification of patients with an increased risk of QTc prolongation when using two or more QTc-prolonging drugs with a known risk of TdP. Includes seven risk factors that are predictors of QT prolongation. Development of the tool might have had selection bias as the prevalence of QT prolongation was quite high compared with the overall prevalence found in the literature review. Also, the tool does not take into account the variety of QT drug–drug interactions. This could be due to the fact that stratification of QT drug–drug interactions is extremely complex and will most likely require a clinical decision in the absence of clear studies in this area.
Sharma clinical decision support system. 39	A clinical decision support system to prevent the use of QT-prolonging medications in the hospital setting. Detects patients at risk of significant QT prolongation (QTc >500 ms) and alerts providers ordering QT-prolonging drugs. ECGs are automatically screened and those with significant QT prolongation (QTc >500 ms for adults; >470 ms for paediatric patients) have “Prolonged QT” documented in their records. When QT-prolonging drugs are ordered in a patient previously identified as having significant QT prolongation, the prescriber is alerted. The alert presents the name of the drug, level of the risk (risk of or possible risk of TdP), any QT-prolonging drug already on the medication list, and a link to online educational resources with more information on how to manage QT prolongation.
Hincapie-Castillo predictive model for drug-associated QT prolongation. 40	A model for predicting severe QT interval prolongation in hospitalised patients using inpatient electronic health record data. The model includes 26 factors for predicting the 24-hour risk of QT events on hospital day 1 and on hospital days 2–5.
Bindraban risk model for predicting QTc interval prolongation in patients using QTc-prolonging drugs. 41	A risk model to predict QTc interval prolongation of eligible ECGs. The model was developed by examining ECGs recorded in patients using one or more QTc-prolonging drugs. Independent risk factors for QTc interval prolongation were determined and risk scores were assigned. The model predicts the risk of QTc interval prolongation.

CCCU, cardiac critical care unit; ECG, electrocardiogram; ICU, intensive care unit; QTc, corrected QT; TdP, Torsades de Pointes.