Stool specimen for diagnosis of pulmonary tuberculosis in adults: protocol for a systematic review and meta-analysis

Abstract

Introduction: Tuberculosis (TB) continues to be a significant health burden, most commonly affecting the lungs and referred to as pulmonary TB (PTB). Diagnostic techniques of PTB primarily rely on expectorated sputum samples. However, the diagnostic yields are often hindered due to insufficient volume and quality of the sputum specimens. Moreover, some individuals are unable to provide sputum samples due to scanty sputum production or difficulty in coughing up and require an invasive procedure to obtain a respiratory sample, such as bronchoscopic or gastric aspiration. Thus, challenges in the acquisition of respiratory specimens warrant an alternate specimen. Therefore, this systematic review aims to evaluate the diagnostic accuracy of a stool specimen for the diagnosis of PTB in adults.

Methods and analysis: We will search MEDLINE (Ovid), Embase (Ovid), Web of Science and Cochrane database from inception to April 2021 using a comprehensive search strategy. Two reviewers will independently perform screening, data extraction and quality assessment. The risk of bias assessment and applicability of results of eligible studies will be performed using the Quality of Diagnostic Accuracy Studies-2 tool. Bivariate random-effects models will be performed to calculate pooled sensitivity, specificity, positive likelihood ratio and negative likelihood ratio and diagnostic odds ratio along with 95% CI of stool specimen for each reported diagnostic method against any of the reference standard test (ie, mycobacterial culture or smear microscopy or Xpert assay using respiratory specimens). Heterogeneity between studies will be assessed by I² statistics and Q statistic of the χ² test.

Ethics and dissemination: The results will be disseminated through publishing in a peer-reviewed medical journal and public presentations in relevant national and international conferences. As this is a systematic review of publicly available data, ethics approval is not required.

Prospero registration number: CRD42021245203.

Keywords: bacteriology; diagnostic microbiology; molecular diagnostics; tuberculosis.