Adverse events.

Extensively drug–resistant (XDR) and pre-XDR- tuberculosis (TB) account for approximately a third of pediatric MDR–TB cases globally. Clinical management is challenging; recommendations are based on limited evidence. We assessed the clinical outcomes for children and adolescents treated for XDR–and pre–XDR–TB. We performed a systematic review and meta–analysis of published studies reporting treatment outcomes for children and adolescents with XDR–and pre–XDR–TB. MEDLINE, EMBASE, Scopus, Web of Science, Google Scholar, and trial registries up to 31 December 2023 were searched. Eligible studies included children and adolescents aged <18 years with XDR–or pre–XDR–TB. The primary outcome was treatment success, defined as a composite of cure and treatment completion. Secondary outcomes were death, failure/ lost to follow–up and adverse events. We identified 34 population-based studies and 14 case studies, which reported treatment outcomes for a total of 656 patients. Treatment durations ranged from 6 to 27 months; follow–up after treatment completion ranged from 2 months to 4 years. The pooled estimate for treatment success in XDR–and pre-XDR-TB was 88·9% (95%CI: 59·7–100%) and 65·4% (95%CI: 27·7–100%), respectively. Drug adverse effects were reported in 56.4% (95%CI: 9.9–100%) and 68.2% (95%CI: 0–100%) of children respectively. Few childhood XDR- and pre-XDR-TB cases are reported. The relatively good treatment outcomes in children compared to adults may be partly due to publishing bias. Drug adverse effects are common.