Indoor air pollution from solid fuel and tuberculosis: a systematic review and meta-analysis

OBJECTIVE: To conduct an updated systematic review and meta-analysis on the association between indoor air pollution and tuberculosis (TB). DESIGN: We searched for English or Chinese articles using PubMed and EMBASE up to 28 February 2013. We aimed to identify randomised controlled trials and observational epidemiological studies that reported the association between domestic use of solid fuel and TB. Two reviewers independently extracted the information from included studies and assessed the risk of bias of these studies using pre-defined criteria. The effect sizes of eligible studies were pooled using a random-effects model; the heterogeneity across studies was quantified using I-2 statistics. RESULTS: We identified 15 studies on solid fuel use and active TB and one on solid fuel use and latent tuberculous infection. The summary odds ratios from case-control and cross-sectional studies were respectively 1.17 (95%CI 0.83 - 1.65) and 1.62 (95%CI 0.89 - 2.93), with substantial between-study heterogeneity (12 56.2% and 80.5%, respectively). Subgroup analysis and meta-regression analysis did not identify any study-level factors that could explain the heterogeneity observed. CONCLUSION: The level of evidence for the association between domestic use of solid fuels and TB was very low. High-quality studies are badly needed to clarify this association and to estimate the magnitude of the problem.