Referee 1's review:

This study provides an up-to-date systematic review about the use of nucleic acid amplication tests for the diagnosis of pulmonary tuberculosis using respiratory specimens. The study is thoroughly researched, carefully analyzed, and clearly presented. My only concern is whether the work adds substantially to the literature on this topic. As the authors appropriately cite, several narrative reviews and meta-analyses have already been published about this topic. One of the take-home messages from this meta-analysis, curiously enough, is to deregard the summary sensitivity and specificity estimates of previous meta-analyses, because the studies are too heterogenous. The authors do note the unique contribution of this manuscript to the literature, which is their meta-regression looking at factors associated with studies that show increased diagnostic accuracy. Nevertheless, I think the manuscript could be strengthened by a few sentences emphasizing why this meta-analyses, other than merely being more up-to-date, is a worthy addition to the meta-analyses already published, some of which the authors have written.

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N.B. These are the comments made by the referee when reviewing an earlier version of this paper. Prior to publication the manuscript has been revised in light of these comments and to address other editorial requirements.