Stream Stage 2 regimen description.

Treatment of rifampicin-resistant tuberculosis (RR-TB) involves drugs that can prolong the QT interval. There is limited data on risk factors and the level of cardiac monitoring required. We analysed STREAM Stage 2 data to address these issues. A post-hoc analysis was undertaken of data from participants allocated to 3 regimens: 9-month control (n = 202), 9-month oral (n = 211) and 6-month (n = 143). Risk factors for development of a QT or QTcF (corrected QT interval [Fredericia’s formula]) interval ≥500ms were assessed. The diagnostic accuracy of a monitoring strategy for QT/QTcF prolongation was tested. QT/QTcF ≥ 500ms occurred on all regimens: 9-month control (n = 14 (6.9%)), 9-month oral (n = 8 (3.8%)) and 6-month (n = 6 (4.2%)). The participating country with the highest number of QT/QTcF interval ≥500ms events was Mongolia (18 events [64%]). A higher baseline QTcF was significantly associated with development of QT/QTcF ≥ 500ms (OR 1.05; 95% CI 1.03 to 1.07, p