Treatment regimens for rifampicin-resistant tuberculosis: highlighting a research gap.

Treatment guidance for non-multidrug-resistant (MDR) rifampicin-resistant (RMP-R) tuberculosis (TB) is variable. We aimed to undertake a systematic review and meta-analysis of the randomised controlled trial (RCT) data behind such guidelines to identify the most efficacious treatment regimens. Ovid MEDLINE, the Web of Science and EMBASE were mined using search terms for TB, drug therapy and RCTs. Despite 12 604 records being retrieved, only three studies reported treatment outcomes by regimen for patients with non-MDR RMP-R disease, preventing meta-analysis. Our systematic review highlights a substantial gap in the literature regarding evidence-based treatment regimens for RMP-R TB.

What are the most efficacious treatment regimens for isoniazid-resistant tuberculosis? A systematic review and network meta-analysis.

INTRODUCTION: Consensus on the best treatment regimens for patients with isoniazid-resistant TB is limited; global treatment guidelines differ. We undertook a systematic review and meta-analysis using mixed-treatment comparisons methodology to provide an up-to-date summary of randomised controlled trials (RCTs) and relative regimen efficacy. METHODS: Ovid MEDLINE, the Web of Science and EMBASE were mined using search terms for TB, drug therapy and RCTs. Extracted data were inputted into fixed-effects and random-effects models. ORs for all possible network comparisons and hierarchical rankings for different regimens were obtained. RESULTS: 12 604 records were retrieved and 118 remained postextraction, representing 59 studies-27 standalone and 32 with multiple papers. In comparison to a baseline category that included the WHO-recommended regimen for countries with high levels of isoniazid resistance (rifampicin-containing regimens using fewer than three effective drugs at 4 months, in which rifampicin was protected by another effective drug at 6 months, and rifampicin was taken for 6 months), extending the duration of rifampicin and increasing the number of effective drugs at 4 months lowered the odds of unfavourable outcomes (treatment failure or the lack of microbiological cure; relapse post-treatment; death due to TB) in a fixed-effects model (OR 0.31 (95% credible interval 0.12-0.81)). In a random-effects model all estimates crossed the null. CONCLUSIONS: Our systematic review and network meta-analysis highlight a regimen category that may be more efficacious than the WHO population level recommendation, and identify knowledge gaps where data are sparse. SYSTEMATIC REVIEW REGISTRATION NUMBER: PROSPERO CRD42014015025.