Cochrane Handbook for Systematic Reviews of Interventions version 6.2В (updated FebruaryВ 2021).

In: Higgins JPT, Thomas J, Chandler J, Cumpston M, Li T, Page MJ, Welch VA (editors). Chapter 3: Defining the criteria for including studies and how they will be grouped for the synthesis. Review authors should plan at the protocol stage how the different populations, interventions, outcomes and study designs within the scope of the review will be grouped for analysis.Д¬ite this chapter as: McKenzie JE, Brennan SE, Ryan RE, Thomson HJ, Johnston RV, Thomas J. Critical and important outcomes should be limited in number and include adverse as well as beneficial outcomes. It is rare to use outcomes as eligibility criteria: studies should be included irrespective of whether they report outcome data, but may legitimately be excluded if they do not measure outcomes of interest, or if they explicitly aim to prevent a particular outcome.Д¬ochrane Reviews should include all outcomes that are likely to be meaningful and not include trivial outcomes.

The population, intervention and comparison components of the question, with the additional specification of types of study that will be included, form the basis of the pre-specified eligibility criteria for the review. The acronym PICO (population, interventions, comparators and outcomes) helps to serve as a reminder of these. The scope of a review is defined by the types of population (participants), types of interventions (and comparisons), and the types of outcomes that are of interest.

Comprehensive meta analysis chapter 19