Table 3.

Best evidence synthesis guidelines ([20]

adapted from Kenney et al. 2010

Level of evidence	Minimum quality	Minimum quantity	Consistency	Terminology for messages
Strong	High (> 85%)	Three	Three high quality studies agree If more than three studies, 3/4th of the medium and high quality studies agree	Recommendations
Moderate	Medium (50–85%)	Two high quality OR Two medium quality and one high quality	Two high quality studies agree OR Two medium quality studies and one high quality study agree. If more than three studies, more than 2/3rd of the medium and high quality studies agree	Practice considerations
Limited	Medium (50–85%)	One high quality OR Two medium quality OR One medium quality and one high quality	If two studies (medium and/or high quality), agree If more than two studies, more then 1/2 of the medium and high quality studies agree
Mixed	Medium and high	Two	Findings from medium and high quality studies are contradictory
Insufficient	No high quality studies, only one medium quality study, and/or any number of low quality studies