Strength of Evidence (KT Strategies Database)

The strength of evidence is examined in terms of the rigor of the research supporting the informational material and its recommendations. The following scale of 1-5 describes the supporting evidence observed during the review of the product.

Scale Evidence


Supporting evidence is based on opinion of the author(s).


Supporting evidence is based on expert opinions of expert panels, committees, professional associations, or consumer organizations or other stakeholder groups.


Supporting evidence is based on qualitative or quantitative research study designs that are non-randomized, controlled, cohort based, case series, case-controlled, cross sectional, survey or descriptive/exploratory in nature. Innovative technologies/devices are supported by consumer efficacy reviews and evaluations.


Supporting evidence is based on mixed method research designs and/or randomized controlled trials with small sample sizes showing statistically non-significant trends and may show false negative results. Technologies and devices are tested rigorously by substantial number of consumers demonstrating similar consistent results when used.


Supporting evidence is based on a large, long-term randomized controlled trial or systematic reviews/meta-analyses of randomized controlled trials of smaller sample sizes that yield sufficient power to confidently predict cause and effect or answer the questions "what works." Technologies/devices are supported by user data demonstrating measured effectiveness and benefit sufficient to support predictable widespread use or technology transfer.