Clearly defined study objective

Appropriate design for study question

Inclusion and exclusion criteria clear and appropriate

Representative sample (and comparison)

Sample size calculation presented

Appropriate selection of outcome

Appropriate measurement of outcome

Standardised collection of data

Adequate length of follow up for research question

Baseline participation >70% (all groups)

Losses and drop outs <20%

Adequate description of losses and completers

Appropriate analysis of outcomes measured

Numerical description of important outcomes given

Adjusted and unadjusted calculations provided (with CI if appropriate)