Prof Jane Noyes, Bangor University and Dr Graham Moore, Cardiff University
The Challenge
The 2030 Agenda for Sustainable Development calls for real transformation and approaches that address the complex underlying causes of ill health and inequality in order to achieve lasting improvements in health for all. However, governments and programmes struggle to make evidence-informed decisions to achieve these ambitious goals.
A core function of World Health Organization (WHO) is to develop guidelines that lay down recommendations designed to support policy-makers and programme managers. Recommendations in WHO guidelines are based on scientific evidence. Important steps in the process for guideline development include devising key question, evaluating the quality of evidence and synthesising the effects of interventions. But the systematic review methods used in these steps were originally developed for clinical interventions such as medicines and are ill-suited for complex public health and health system interventions.
In order to address the challenges and realities of complex public health and health system interventions and to better meet the needs of decision-makers, WHO commissioned a set of papers on methods that could be used for evidence-informed decisions about health, addressing intricate and complex health interventions and systems.

Series of Papers
A steering group at WHO, identified leading international experts, which included NCPHWR researchers (Professor Jane Noyes, Bangor University and Dr Graham Moore, Cardiff University), to form work groups in a variety of relevant disciplines to produce the series of papers. The eight papers in this series are directed at the steps in the WHO guideline development process as summarised in the illustration below.
- The first four papers explore concepts, formulate questions and set the stages for the papers that follow – which go on to address more specific issues.
- The next three papers in the series:
- Discuss evidence synthesis (the understanding of individual studies within the context of global knowledge)
- Look at the implications of taking a complexity perspective when producing quantitative, qualitative and mixed-methods of evidence (complexity perspective is where a set of frameworks is used for developing and studying complex systems).
- The final paper in the series considers the implications of complexity in the assessment of the quality of the evidence.
The Impact
This collection of papers has global significance and contributes to the understanding of the complexity and the implications for guidelines development. The series outlines approaches and tools that can help reviewers and those developing guidelines take complexity into account.
The findings from the papers can be used to strengthen WHO’s own guideline development process and contribute to global information and discussions – ensuring that the newest guidelines are relevant, and help Member States to achieve the sustainable development goals by 2030.
View the full series of papers here:
Complex health interventions in complex systems: improving the process and methods for evidence-informed health decisions https://gh.bmj.com/content/4/Suppl_1/e000963
Implications of a complexity perspective for systematic reviews and guideline development in health decision making https://gh.bmj.com/content/4/Suppl_1/e000899
Taking account of context in systematic reviews and guidelines considering a complexity perspective https://gh.bmj.com/content/4/Suppl_1/e000840
The WHO-INTEGRATE evidence to decision framework version 1.0: Integrating WHO norms and values and a complexity perspective https://gh.bmj.com/content/4/Suppl_1/e000844
Formulating questions to address the acceptability and feasibility of complex interventions in qualitative evidence synthesis https://gh.bmj.com/content/4/Suppl_1/e001107
Synthesizing quantitative evidence in systematic reviews of complex health interventions https://gh.bmj.com/content/4/Suppl_1/e000858
Qualitative evidence synthesis for complex interventions and guideline development: clarification of the purpose, designs and relevant methods https://gh.bmj.com/content/4/Suppl_1/e000882
Synthesising quantitative and qualitative evidence to inform guidelines on complex interventions: clarifying the purpose, designs and outlining some methods https://gh.bmj.com/content/4/Suppl_1/e000893