Table 1

Checklist for epidemiological and statistical reviews

Design:
  Is there a clear statement of the study objectives?
  Is there a clear description of the study design?
  Is the study design appropriate?
  In there a clear description of the study populations?
  Is there a clear description of how the main variables were measured?
  Is there an assessment of the adequacy of the sample size?
Presentation and analysis:
  Are the statistical procedures adequately described or referenced?
  Are the statistical procedures appropriate?
  Are the response rates reported?
  Are the data and the results adequately described?
  Are confidence intervals and significant levels given where appropriate?
Bias and confounding:
  Are the response or tracing rates satisfactory?
  Are you reasonably satisfied that the results are not explained by bias in subject selection or  measurement?
  As far as you can tell, have confounding variables been taken into account appropriately— either in the analysis or in the discussion?