1. Is the hypothesis or objective clearly stated? | 2. Are the main outcomes to be measured clearly described? | 3. Are the characteristics of the participants clearly described? | 5. Are the distributions of principle confounders clearly described? | 6. Are the main findings of the study clearly described? | 7. Estimates of the random variability in the data for the main outcome? | 10. Have actual probability values been reported? | 11. Were the subjects asked representative of the entire population? | 12. Were those subjects used representative of the entire population? | 16. Were any of the results based on “data dredging”? | 18. Were the statistical tests used to assess main outcome measures appropriate? | 20. Were the main outcome measures used accurate? (valid and reliable?) | 21. Were cases and controls from the same population? | 22. Were the cases and controls recruited over the same period of time? | 25. Was there adequate adjustment for confounding in the analysis? |