Table 1.

Study inclusion and exclusion criteria

Study types eligible for inclusion

Study types that were excluded

• Observational/uncontrolled cohort studies (prospective/retrospective longitudinal studies, cross-sectional studies) • Studies with both observational and interventional phases • Database studies, registries • Studies with no available abstract

• Interventional trials (parallel and crossover design, double-blind, single-blind, open label) with no observational phases • Phase I, II, III or IV studies • Case reports or case series • Case–control studies • In vitro studies/genetic studies/molecular epidemiology studies • Imaging/diagnostic studies; studies assessing techniques • Classification schemes (e.g. studies assessing staging schemes) • Studies focusing on pathophysiology or prevention • Systematic reviews • Editorials, letters, comments, non-systematic review articles • Guidelines • Policy/prioritisation papers/research recommendations