Table 8. Quetiapine versus placebo on QT interval in people with mental disorders.
| Outcome | Risk with intervention per 1,000 | Risk with comparator per 1,000 | Relative measure of association | Number of participants (studies) | Quality (GRADE) | Comments† |
|---|---|---|---|---|---|---|
| Quetiapine in children and adolescents | ||||||
| Corrected QT (QTc) changes | NR | NR | MD 0.62 (−4.15, 5.39); SMD 0.02 (−0.10, 0.14) | 1,298 (5 studies) (35) | Very low | No difference |
| QT prolongation | NR | NR | Adjusted OR 1.39 (0.45, 2.33) | 3,472,494 [1 observational study of FDA Adverse Event Reporting System (FAERS)] (25) | Very low | No difference |
| Quetiapine in adults | ||||||
| QT prolongation | 3 | 0 | RR 2.87 (0.12, 70.08) | 546 (3 RCTs) (80,81,86) | Low | No difference |
| QTc prolongation | NR | NR | MD 9.90 (2.10, 17.80) | 72 (1 RCT) (80) | Very low | Favors control, no quetiapine |
| QTcLD >60 msec | 0 | 0 | RR 0.00 (0.00, 0.00) | 65 (1 RCT) (81) | Very low | No difference |
| QTcLD increase 30–60 msec | 47 | 45 | RR 1.02 (0.10, 10.67) | 65 (1 RCT) (81) | Very low | No difference |
| QTc changes | NR | NR | MD 8.10 (1.64, 14.56); SMD 0.67 (0.14, 1.19) | 65 (1 RCT) (81) | Very low | Favors control, no quetiapine |
| QTc prolongation | NR | NR | Adjusted MD 0.11 (−0.87, 1.09) | 1,017 (1 observational study) (24) | Very low | No difference |
| Torsade’s de Pointes and/or QT interval abnormalities (>4 cases) | NR | NR | Adjusted OR 4.78 (3.91, 5.85) | 67,992 [1 observational study of FDA Adverse Event Reporting System (FAERS)] (34) | Very low | Favors control, no quetiapine |
| Torsade’s de Pointes to sudden cardiac death, >4 cases | NR | NR | Adjusted OR 1.31 (1.23, 1.39) | 67,992 [1 observational study of FDA Adverse Event Reporting System (FAERS)] (34) | Very low | Favors control, no quetiapine |
†, we concluded that there is no difference in outcomes between active and control interventions based on P value >0.05 and inability to reject null hypotheses but without post-hoc analysis of the statistical power to detect true differences. 95% confidence interval in (); GRADE, Grading of Recommendations Assessment, Development and Evaluation; OR, odds ratio; RCT, randomized controlled trial; RR, relative risk; MD, mean difference; SMD, standardized mean difference between intervention and comparator where the magnitude of the effect is defined as small (SMD, 0−0.5 standard deviations), moderate (SMD, 0.5−0.8 standard deviations), and large (SMD >0.8 standard deviations); QTcLD, interval corrected for heart rate using the population specified linear derived method; NR, not reported.