Table 4: Level of evidentiary support across systematic reviews. For syntheses with limited number of studies, we looked at the high-, moderate-, low-quality reviews and the original methodological review tool for making conclusions about strength of evidence.

STRONG: (over 70% effect positive—eg 5/7 positive) AND A minimum of 3 strong evidence A minimum of 2 strong AND 2 moderate evidence

MODERATE: (60%–69% effect positive—eg 3/5 positive) AND A minimum of 1 strong AND 2 moderate evidence A minimum of 3 moderate evidence

LIMITED: (50%–59% effect positive) AND A minimum of 1 moderate and 2 weak/limited evidence A minimum of 3 weak/limited evidence

INCONSISTENT: (50% or less of a positive effect) Does not meet the above criteria

INSUFFICIENT: Information is not inconsistent but does not meet the criteria for weak evidence