Evidence-Based Tuberculosis Diagnosis
Madhukar Pai*, Andrew Ramsay, Richard O'Brien
With the publication of several systematic reviews, there is now a strong evidence base to support global policy on TB diagnostics. A key challenge is to maintain the momentum gained in the past few years, and expand the scope and role of evidence synthesis to outcomes that go beyond conventional diagnostic accuracy. These outcomes include: accuracy of diagnostic algorithms (rather than single tests) and their relative contributions to the health care system; incremental or added value of new tests; impact of new tests on clinical decision-making and therapeutic choices; cost-effectiveness in routine programmatic settings; impact on patient-centered outcomes; and societal impact of new tools. Indeed, the GRADE (Grading of Recommendations Assessment, Development and Evaluation) approach to grading the quality of evidence and strength of recommendations for diagnostic tests recognizes that diagnostic accuracy results are surrogates for patient-centered outcomes, and emphasizes that diagnostic tests are of value only if they result in improved outcomes for patients.
In addition to expanding the scope of evidence synthesis, it is also important to ensure that systematic reviews stay current by including new literature. Periodic updates are needed to ensure that systematic reviews provide the most current evidence available for clinical and policy decisions. For example, the literature on IGRAs has exploded in the past few years, and this necessitated an updated meta-analysis on this topic.
Recognizing the growing importance of evidence-based TB diagnosis and policy making, the Stop TB Partnership's New Diagnostics Working Group has recently created a new subgroup on Evidence Synthesis for TB Diagnostics. This subgroup will support the development of new systematic reviews, facilitate the development and dissemination of evidence summaries on new diagnostics, and actively promote their use in guideline and policy development processes, along the lines of the GRADE approach.
Funding: MP is a recipient of a New Investigator Career Award from the Canadian Institutes of Health Research. This agency had no involvement in the preparation of this manuscript.
Competing Interests: The authors have no financial conflicts of interest. All the authors are members of the Stop TB Partnership's Working Group on New Diagnostics. AR is the secretary of the Working Group. MP and ROB are co-chairs of the Working Group's subgroup on Evidence Synthesis for TB Diagnostics. ROB works for the Foundation for Innovative New Diagnostics, a nonprofit agency that collaborates with several industry partners for the development of new diagnostics for neglected infectious diseases. No industry partner was involved in the preparation of this manuscript.
Citation:Pai M, Ramsay A, O'Brien R (2008) Evidence-Based Tuberculosis Diagnosis. PLoS Med 5(7): e156 doi:10.1371/journal.pmed.0050156
Published: July 22, 2008
Copyright:© 2008 Pai et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Abbreviations: ADA, adenosine deaminase; BCG, bacille Calmette-Guérin; FIND, Foundation for Innovative New Diagnostics; IFN-γ, interferon-gamma; IGRA, interferon-gamma release assay; LED, light-emitting diode; MDR-TB, multidrug-resistant tuberculosis; NAAT, nucleic acid amplification test; STAG-TB, Strategic and Technical Advisory Group for Tuberculosis; TB, tuberculosis; TDR, UNICEF/UNDP/World Bank/WHO Special Programme for Research and Training in Tropical Diseases; TST, tuberculin skin test; WHO, World Health Organization; XDR-TB, extensively drug-resistant tuberculosis
Madhukar Pai is with the Department of Epidemiology, Biostatistics and Occupational Health, McGill University, Montreal, Quebec, Canada. Andrew Ramsay is with the UNICEF/UNDP/World Bank/WHO Special Programme for Research and Training in Tropical Diseases, World Health Organization, Geneva, Switzerland. Richard O'Brien is with the Foundation for Innovative New Diagnostics, Geneva, Switzerland.
* To whom correspondence should be addressed. E-mail: madhukar.pai@mcgill.ca
