Cochrane Reviews are becoming increasingly complex as methods evolve, as data sources become more diverse, and as we increasingly recognize that health outcomes are the products of many interlinked elements. Cochrane pioneered the publication of protocols before undertaking systematic reviews, partly to help ensure that the many decisions we make along the way are objective and not based on the results of the identified studies.
These series of presentations were originally part of the 2019 Cochrane Methods Symposium. 2019's Methods Symposium examined whether our protocols continue to provide the road map we need to navigate a modern Cochrane Review. The speakers explored how much can reasonably be anticipated about the decisions we need to make. They addressed several aspects of pre-specification from diverse methodological perspectives, showcasing updated material in the new Cochrane Handbook for Systematic Reviews of Interventions (Version 6). Issues for discussion included deciding what syntheses are to be performed, deciding which data to extract and analyse, and dealing with issues of complexity in interventions and study contexts. The extent to which issues can be overcome with careful review planning is discussed, as well as determining whether refinements are needed in our current guidance for writing protocols. The Symposium is intended for the wider Cochrane community.
The session is particularly useful for Cochrane Review Group editors, methodologists and others involved in review production, as well as those who are interested in understanding considerations for developing robust Cochrane Review protocols with increasingly diverse evidence.
We have edited the presentations from the symposium into several sections, which you can view at the following links:
- Part 1: Welcome to the 2019 Methods Symposium (Julian Higgins)
- Part 2: General issues in pre-specification (James Thomas)
- Part 3:The notion of PICO for synthesis: planning the grouping of studies for meta-analyses and other syntheses (Sue Brennan)
- Part 4: Planning a Cochrane review to compare multiple interventions – the role of network meta-analysis (Tianjing Li)
- Part 5: Issues to consider when including qualitative evidence (Angela Harden)
- Part 6: The problem of multiplicity and the use of hierarchical selection rules (Matthew Page)
- Part 7: Special issues for addressing adverse effects (Daniela Junqueira)
- Part 8: Issues in reviews of test accuracy (Yemisi Takwoingi)
- Part 9: Questions and answers