Do the tuberculin skin test and the QuantiFERON-TB Gold in-tube test agree in detecting latent tuberculosis among high-risk contacts? A systematic review and meta-analysis

OBJECTIVES: The QuantiFERON-TB Gold in-tube test (QFT-GIT) and the tuberculin skin test (TST) are used to diagnose latent tuberculosis infection (LTBI). However, conclusive evidence regarding the agreement of these two tests among high risk contacts is lacking. This systematic review and meta-analysis aimed to estimate the agreement between the TST and the QFT-GIT using kappa statistics. METHODS: According to the Preferred Reporting Items for Systematic Review and Meta-Analyses guidelines, scientific databases including PubMed, Scopus, and Ovid were searched using a targeted search strategy to identify relevant studies published as of June 2015. Two researchers reviewed the eligibility of studies and extracted data from them. The pooled kappa estimate was determined using a random effect model. Subgroup analysis, Egger’s test and sensitivity analysis were also performed. RESULTS: A total of 6,744 articles were retrieved in the initial search, of which 24 studies had data suitable for meta-analysis. The pooled kappa coefficient and prevalence-adjusted bias-adjusted kappa were 0.40 (95% confidence interval [CI], 0.34 to 0.45) and 0.45 (95% CI, 0.38 to 0.49), respectively. The results of the subgroup analysis found that age group, quality of the study, location, and the TST cutoff point affected heterogeneity for the kappa estimate. No publication bias was found (Begg’s test, p=0.53; Egger’s test, p=0.32). CONCLUSIONS: The agreement between the QFT-GIT and the TST in diagnosing LTBI among high-risk contacts was found to range from fair to moderate.