Table 1. National Health and Medical Research Council hierarchy of evidence-based scientific studies.
Level | Intervention |
---|---|
I | A systematic review of level II studies |
II | A randomized controlled trial |
III-1 | A pseudorandomized controlled trial (ie, alternate allocation or some other method) |
III-2 | A comparative study with concurrent controls: Non-randomized experimental trial Cohort study Case–control study Interrupted time series with a control group |
III-3 | A comparative study without concurrent controls Historical control study Two or more single-arm study Interrupted time series without a parallel control group |
IV | Case series with either post-test or pretest/post-test outcomes |