Use of systematic reviews in WHO recommendations

Are current standards of reporting quality for clinical trials sufficient in addressing important sources of bias?

Determining the quality of a randomized clinical trial (RCT) is necessary for decision-makers to determine the believability and applicability of the trial findings. Issues that are likely to affect the utility of RCT evidence include issues of bias, random error and applicability. In this article we focus primarily on issues of bias and examine the evidence for whether reporting methodological items, including allocation concealment, sequence generation, and blinding of participants can be relied upon as evidence of bias. We present the findings of a systematic review of meta-epidemiological studies and a simulation study demonstrating that commonly examined sources of bias likely play little role in treatment exaggeration. We discuss other issues that may additionally influence trial outcomes including sample size, publication bias, and expertise of trialists. We conclude by discussing strategies to moderate the effect of known biases in assessing overall estimates of treatment effects.

Appraisal of guidelines developed by the World Health Organization

OBJECTIVE

To appraise the quality of guidelines developed by the World Health Organization (WHO) that were approved by its Guidelines Review Committee (GRC) and identify strengths and weaknesses in the guideline development process.

STUDY DESIGN

Cross-sectional.

METHODS

Three individuals independently assessed GRC-approved WHO guidelines using the Appraisal of Guidelines for Research and Evaluation II instrument (AGREE II). Scores were standardized across domains and overall quality was determined through consensus.

RESULTS

124 guidelines met inclusion criteria and were assessed. 58 guidelines were recommended for use, 58 were recommended with modifications and eight were not recommended. The highest scoring domains across guidelines were scope and purpose, and clarity of presentation. The recommended guidelines had higher rigor of development and applicability domain scores in comparison to other guidelines. 77% of the guidelines referenced an underlying evidence review and 49% used GRADE to assess the body of evidence or the strength of the recommendation. The domains in need of improvement included stakeholder engagement, editorial independence, and applicability. Guidelines not recommended for use were generally insufficient in their rigor of development.

CONCLUSIONS

WHO guidelines need further improvement, most importantly in the rigor of their development (i.e., use of evidence reviews). Other areas for improvement include increased stakeholder engagement, a more explicit process for recommendation formulation and disclosure of interests, discussion of the facilitators, barriers, resource implications, and criteria for monitoring the outcomes of guideline implementation. WHO guidelines can improve through increased transparency, adherence to the WHO Handbook for Guideline Development, and better oversight by the GRC.

Global health: the importance of evidence-based medicine

Global health is a varied field that comprises research, evaluation and policy that, by its definition, also occurs in disparate locations across the world. This forum article is introduced by our guest editor of the Medicine for Global Health article collection, Gretchen Birbeck. Here, experts based across different settings describe their personal experiences of global health, discussing how evidence-based medicine in resource-limited settings can be translated into improved health outcomes.