Question

Describe the levels of evidence and provide an example of the type of practice change that could result from each.

Answer 1

Levels of evidences for evidence practices

Level I : Evidence from a systematic review or meta-analysis of all relevant RCTs (randomized controlled trial) or evidence-based clinical practice guidelines based on systematic reviews of RCTs or three or more RCTs of good quality that have similar results.

Level II : Evidence obtained from at least one well-designed RCT (e.g. large multi-site RCT)

Level III : Evidence obtained from well-designed controlled trials without randomization (i.e. quasi-experimental).

Level IV : Evidence from well-designed case-control or cohort studies.

Level V : Evidence from systematic reviews of descriptive and qualitative studies (meta-synthesis).

Level VI : Evidence from a single descriptive or qualitative study.

Level VII : Evidence from the opinion of authorities and/or reports of expert committees