Pretreatment attrition after rifampicin-resistant tuberculosis diagnosis with Xpert MTB/RIF or ultra in high TB burden countries: a systematic review and meta-analysis.

Introduction: The WHO endorsed the Xpert MTB/RIF (Xpert) technique since 2011 as initial test to diagnose rifampicin-resistant tuberculosis (RR-TB). No systematic review has quantified the proportion of pretreatment attrition in RR-TB patients diagnosed with Xpert in high TB burden countries.Pretreatment attrition for RR-TB represents the gap between patients diagnosed and those who effectively started anti-TB treatment regardless of the reasons (which include pretreatment mortality (death of a diagnosed RR-TB patient before starting adequate treatment) and/or pretreatment loss to follow-up (PTLFU) (drop-out of a diagnosed RR-TB patient before initiation of anti-TB treatment).