Table 1.

Eligibility criteria.

Inclusion criteria

Exclusion criteria

• Human participants: adults and children • Primary research, published from 1 January 1946 to 31 August 2020 • Study designs: trials including randomized controlled trials (RCTs), crossover trials, pre-post trials, pre-post one arm trials, post-only trials and any design with a comparative arm. Crossover trials were required to have a minimum “washout period” of seven days between intervention arms. • Full text available in English

• Systematic or narrative reviews • Non-experimental studies • Laboratory-based studies • Non-adherence to experimental allocation. That is, any trial where the original participant allocation to intervention / control had been changed on any basis, such as self-reported behavior, assessed level of use of active intervention. • Conference abstracts • Incomplete datasets