Table 3.

Evidence criteria for the best-evidence synthesis

Evidence category	Criteria
Very strong evidence	Four or more high quality studies, where ≥ 80% of the findings consistently support moderation or mediation
Strong evidence	Four or more acceptable quality studies, where ≥ 80% of the findings consistently support moderation or mediation
Moderate evidence	Two or more high/acceptable studies, where ≥ 60% of the findings consistently support moderation or mediation
	OR
	Two or more low quality studies, where ≥ 80% of the findings consistently support moderation or mediation
Limited evidence	Evidence provided by one study, or by all low-quality studies
Conflicting evidence	Inconsistent findings across multiple studies (< 60% of studies report consistent findings)
No evidence	No studies support mediation or moderation regardless of the number or quality of studies