Registered Nurses' Association of Ontario

Levels of Evidence

 

Ia

Evidence obtained from meta-analysis or systematic reviews of randomized controlled trials.

Ib

Evidence obtained from at least one randomized controlled trial.

IIa

Evidence obtained from at least one well-designed controlled study without randomization.

IIb

Evidence obtained from at least one other type of well-designed quasi-experimental study, without randomization.

III

Evidence obtained from well-designed non-experimental descriptive studies, such as comparative studies, correlation studies and case studies.

IV

Evidence obtained from expert committee reports or opinions and/or clinical experiences of respected authorities.

Adapted from “Annex B: Key to evidence statements and grades of recommendations,” by the Scottish Intercollegiate Guidelines Network (SIGN), 2012, in SIGN 50: A Guideline Developer’s Handbook. Available from http://www.sign.ac.uk/guidelines/fulltext/50/annexb.html

 

 

Clinical Management
Assessment and Management of Pain - 3rd Edition
Practice Recommendations