Qualitative Evidence Synthesis for TB

Evidence synthesis is an established set of scientific methods to assemble, appraise, and summarize research. This science is an essential component in translating research findings into policy and practice.¹ Increasingly, evidence synthesis of research relevant to effectiveness, acceptability, feasibility, equity, costs, and implementation of interventions is being used to inform policy and guideline recommendations.²

Tuberculosis (TB) is still among the global top causes of mortality. Drug-resistant TB (DR-TB) is now the leading cause of death due to antimicrobial-resistant disease and poses a global security risk.^{3, 4} In 2010, the World Health Organization (WHO) recommended the use of Xpert MTB/RIF (Xpert) as an initial diagnostic test for the detection of TB and rifampicin resistance.⁵ Since then, newer molecular TB tests, Nucleic Acid Amplification Tests (NAATs), have been recommended by WHO as initial diagnostic tests for TB due to their high accuracy, rapid results, and effect on health outcomes.² However, implementation and translation of this global policy into country-level decisions continue to be slow. In 2021, of the 6.4 million people newly diagnosed with TB, only 38% were diagnosed with a WHO recommended rapid molecular diagnostic test.³

Ineffective translation, where a policy or guideline recommendation is adopted too slowly, can compromise effective control of disease. Possible reasons for poor adherence or implementation of health guidelines in various settings can be explored through primary qualitative studies and synthesis of qualitative research. Qualitative evidence synthesis comprises methods for conducting systematic reviews of qualitative research studies, synthesizing perspectives from different settings.^{6, 7} It complements findings from quantitative research by summarizing relevant programmatic information on feasibility, acceptability, equity at global, regional, and national levels.²

To inform the WHO guidelines on rapid diagnostic tests for TB,² we conducted a systematic review of qualitative studies to synthesize end-user and professional user perspectives and experiences with low-complexity NAATs for the detection of TB and DR-TB; and to identify implications for effective implementation and health equity.⁸ Our review complemented findings on systematic reviews for the diagnostic accuracy and impact of TB tests and systematic reviews of economic evaluation of these tests.² Recently, a mixed methods review of 130 quantitative studies, qualitative studies, and operational reports informed the WHO report on universal access to rapid TB diagnostics by assessing implementation solutions to increase the uptake and impact of WHO recommended rapid diagnostic tests.⁹

More qualitative research and evidence syntheses on social determinants of health for TB, equity considerations as well as acceptability and feasibility across various contexts will be useful in guiding effective planning and implementation of TB interventions. We look forward to having a larger community of experts and enthusiasts of qualitative evidence synthesis for TB.

References

1. Donnelly CA BI, Campbell P, Craig C, Vallance P, Walport M, Whitty CJM, Woods E, Wormald C. Four principles to make evidence synthesis more useful for policy. Nature. 2018;558(7710):361-4.
2. WHO. WHO consolidated guidelines on tuberculosis. Module 3: Diagnosis. Rapid diagnostics for tuberculosis detection. Geneva, Switzerland: World Health Organization. 2021. Available at https://www.who.int/publications/i/item/9789240029415
3. WHO. Global Tuberculosis Report. Geneva, Switzerland: World Health Organization. 2022. Available at https://www.who.int/teams/global-tuberculosis-programme/tb-reports/global-tuberculosis-report-2022
4. WHO. Status Update: Reaching the targets in the political declaration of the United Nations General Assembly High-level Meeting on the fight against tuberculosis. September 2023. Geneva, Switzerland: World Health Organization. Available at https://www.who.int/publications/m/item/WHO-UCN-TB-2023.4
5. Albert H, Nathavitharana RR, Isaacs C, Pai M, Denkinger CM, Boehme CC. Development, roll-out and impact of Xpert MTB/RIF for tuberculosis: what lessons have we learnt and how can we do better? Eur Respir J. 2016;48(2):516-25.
6. Atkins S, Lewin S, Smith H, Engel M, Fretheim A, Volmink J. Conducting a meta-ethnography of qualitative literature: lessons learnt. BMC Med Res Methodol. 2008; 8: 21.
7. Noyes J BA, Cargo M, Flemming K, Harden A, Harris J, Garside R, Hannes K, Pantoja T, Thomas J. Chapter 21: Qualitative evidence. In: Higgins JPT TJ, Chandler J, Cumpston M, Li T, Page MJ, Welch VA (editors), ed. Cochrane Handbook for Systematic Reviews of Interventions version 6.4 (updated August 2023): Cochrane.2023. Available at www.training.cochrane.org/handbook
8. Engel N, Ochodo EA, Karanja PW, et al. Rapid molecular tests for tuberculosis and tuberculosis drug resistance: a qualitative evidence synthesis of recipient and provider views. Cochrane Database Syst Rev 2022;4(4):CD014877. doi: 10.1002/14651858.CD014877.pub2
9. Nathavitharana RP, A. OBryan, M. Edwards, et al. WHO Standard: Universal access to rapid tuberculosis diagnostics. Web Annex A. Uniting innovation and implementation: a mixed methods systematic review of implementation solutions to increase the uptake and impact of molecular WHO-recommended rapid diagnostic tests. Geneva, Switzerland: World Health Organization. 2023. Available at https://iris.who.int/bitstream/handle/10665/366684/9789240071339-eng.pdf

About the Author

Eleanor is a Research Scientist and Associate Professor Extraordinary of Clinical Epidemiology at the Kenya Medical Research Institute (KEMRI) and Stellenbosch University, South Africa respectively. She is an academic editor for Cochrane Infectious Diseases Group and conducts systematic reviews on TB diagnostics to inform WHO guidelines. She was awarded the 2019 UK MRC/DFID African Research Leader Grant Award to establish an evidence synthesis unit at KEMRI in collaboration with Stellenbosch University and Liverpool School of Tropical Medicine.