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Canadian Task Force on the Periodic Health Examination’s Levels of Evidence*
| Level | Type of evidence |
|---|---|
| I | At least 1 RCT with proper randomization |
| II.1 | Well designed cohort or case-control study |
| II.2 | Time series comparisons or dramatic results from uncontrolled studies |
| III | Expert opinions |
Adapted from Canadian Task Force on the Periodic Health Examination. The periodic health examination. Can Med Assoc J 1979;121:1193-254
