Table 2.

Australian National Health and Medical Research Council Designated Levels of Evidence¹

Level of evidence	Description
I	Evidence obtained from a systematic review of all relevant randomised controlled trials.
II	Evidence obtained from at least one properly designed randomised controlled trial.
III - 1	Evidence obtained from well designed pseudo-randomised controlled trials (alternate allocation or some other method).
III - 2	Evidence obtained from comparative studies with concurrent controls and allocation not randomised (cohort studies), case control studies or interrupted time series with control group.
III - 3	Evidence obtained from comparative studies with historical control, two or more single arm studies, or interrupted time series without a parallel control group.
IV	Evidence obtained from a case series, either post-test or pre-test and post-test.

¹Data from reference [53]