Registered Nurses' Association of Ontario

Interpretation of Evidence

Types of Evidence

Evidence obtained from meta-analysis or systematic review 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.

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.

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


Chronic Disease
Strategies to Support Self Management in Chronic Conditions
Practice Recommendations