2Evidence for policy formulation

Publication Details

2.1. Synthesis of evidence

In September 2009, WHO assessed the evidence for the efficacy of LED microscopy in a systematic, structured way. The first step was a systematic review and meta-analysis of published and unpublished data with standard methods appropriate for studies of diagnostic accuracy. The second step was the convening of an expert group to evaluate the strength of the evidence, recommend operational and logistical considerations for use of LED microscopy in national TB control programmes and identify gaps to be addressed by future research. The third step was presentation of draft recommendations to the WHO Strategic and Technical Advisory Group for Tuberculosis (STAG-TB) for endorsement.

In accordance with current WHO standards for evidence assessment in the formulation of policy recommendations, the grades of recommendation assessment, development and evaluation (GRADE) system (1) was used by the Expert Group to assess the findings of the systematic review. This approach provides a systematic, structured framework for evaluating both the accuracy of new interventions and their impact on patients and public health.

The Expert Group’s findings and the final GRADE evaluation (2) were presented to STAG-TB in November 2009. STAG-TB recognized that the evidence was compelling and that there was a large body of work on LED microscopy and advised WHO to proceed with policy guidance on its use (3). STAG-TB also asked WHO to prepare an overarching policy framework to guide the use of new TB diagnostics, methods and approaches at country level (3). This document provides a pragmatic summary of the evidence and recommendations for LED microscopy. It should be readin conjunction with the detailed findings of the Expert Group (which include the GRADE tables) and the WHO framework for using TB diagnostics (2). The framework gives the context for use of one or more of the currently approved WHO diagnostic tools and methods in relation to country infrastructure, resources, TB epidemiology and TB policy reform.

The existing TB diagnostic tools are not mutually exclusive: they can be used in various combinations in country screening and diagnostic algorithms, which are highly setting- and resource-specific. Expert laboratory input is therefore needed to define the most cost-effective and efficient algorithms for individual countries, guided by WHO standards (e.g. for laboratory biosafety) and procedures and in the context of overall, integrated, laboratory strengthening.

2.2. Management of declarations of interest

Expert Group members were asked to submit completed declaration of interest forms, which were reviewed by the WHO secretariat before the Expert Group meeting. None of the members declared any conflict of interest. The declaration of interest statements were summarized by the co-chair of the Expert Group meeting at the start of the meeting. No additional declarations were made.

Selected individuals with intellectual or research involvement in LED microscopy were invited as observers to provide technical input and answer technical questions on the methods. These individuals did not participate in the GRADE evaluation and were asked to leave the meeting during the final discussions, when the recommendations were developed. They were also not involved in writing the final meeting report, nor in preparation of the STAG-TB documentation or the final WHO policy statements.

The process for evidence synthesis and policy development was reviewed by the WHO Guidelines Review Committee, and the policy recommendations were approved in June 2010.

The target date for review is 2015.