Recommendations in WHO guidelines are based on sound scientific evidence. Fundamental steps in the process for guideline development include formulating key questions, evidence retrieval and synthesis, and appraisal of the quality of the evidence. But the methods used in these steps were originally conceived for the development of clinical interventions as part of the evidence-based medicine movement. Today, WHO develops guidelines on a broad array of clinical, public health, health system, health promotion and implementation strategies. These interventions are often highly context-specific, with multiple factors that directly and indirectly impact the health and societal outcomes.
Complexities in guideline development
Considering these complexities in each of the steps in guideline development brings many challenges to participants in these processes, including understanding and considering:
- different factors that influence the impact of an intervention;
- how an intervention interacts with context and the different factors that influence the implementation and impact of an intervention;
- the difficulty in attribution of effect when an intervention works best in synergy with other interventions;
- voices of different stakeholders; and
- criteria beyond effectiveness that should be considered when formulating recommendations.
Unless a guideline process encompasses the relevant aspects of complexity, we risk not doing justice to the assessment of the interventions, and our recommendations may not provide countries with the guidance they need to implement these recommendations.
Strengthening WHO’s own guideline development process
Standard guideline development methods need to be enhanced to better address these needs. Recognizing this, WHO commissioned a set of papers on approaches to improve the process and methods used for evidence-informed decisions about health, addressing complex health interventions and complex systems. This collection of papers, published today in BMJ Global Health, contributes to the understanding of complexity and the implications for evidence synthesis and guidelines development, whether at global, national, or health systems level.
The lessons learned from these papers will be used to strengthen WHO’s own guideline development process and contribute to the global literature and discussions to ensure that state of the art guidelines are relevant and impactful at scale, and accelerate progress of Member States to achieve the sustainable development goals by 2030.
The special edition includes the following papers
- Norris S, Rehfuess E, Smith H, et al.. Complex health interventions in complex systems: improving the process and methods for evidence-informed health decisions
- Petticrew M, Knai C, Thomas J, et al. Implications of a complexity perspective for systematic reviews and guideline development in health decision making
- Booth A, Moore G, Flemming K, et al. Taking account of context in systematic reviews and guidelines considering a complexity perspective
- Rehfuess E, Stratil J, Scheel IB, et al. The WHO-INTEGRATE evidence to decision framework version 1.0: Integrating WHO norms and values and a complexity perspective
- Booth A, Noyes J, Flemming K, et al. Formulating questions to address the acceptability and feasibility of complex interventions in qualitative evidence synthesis
- Higgins JP, López-López JA, Becker BJ, et al. Synthesizing quantitative evidence in systematic reviews of complex health interventions
- Flemming K, Booth A, Garside R, et al. Qualitative evidence synthesis for complex interventions and guideline development: clarification of the purpose, designs and relevant methods
- Noyes J, Booth A, Moore G, et al. Synthesising quantitative and qualitative evidence to inform guidelines on complex interventions: clarifying the purpose, designs and outlining some methods
- Montgomery P, Movsisyan A, Grant S, et al. Considerations of complexity in rating certainty of evidence in systematic reviews: a primer on using the GRADE approach in global health