Effectiveness of royal jelly supplementation in glycemic regulation: A systematic review

Table 5 GRADE assessment for acute effects of RJ administration on glycemic control

GRADE criteria	Rating	Support for judgement	Overall quality of evidence
Outcomes: Acute glycemic control outcomes (n = 4 studies)
RoB (assessed on Cochrane RoB Collaboration Tool)	No	Majority of studies had overall high RoB, likely affecting the study results	High
	Serious (-1)
	Very serious (-2)1
Inconsistency	No	Outcome effects are somewhat consistent, and studied population are similar enough to not be considered detrimental to evidence quality. Intervention, however, was heterogeneous across all relevant studies	Moderate
	Serious (-1) 1
	Very serious (-2)
Indirectness	No1	Research question is addressed by majority of the animal studies	Low
	Serious (-1)
	Very serious (-2)
Imprecision	No	All studies have groups with small sample sizes (≤ 20), with no indication that they meet required sample sizes to detect difference in outcome. For those with calculable effect sizes, the confidence intervals suggest potential for no appreciable benefit	Very low1
	Serious (-1)
	Very serious (-2) 1
Publication bias	Undetected1	There is chance of publication bias considering the review is entirely “small-scale” trials; this area of research is not well-established and there is potential for publication bias, but none was overtly detected
	Strongly suspected (-1)
Other	Large effect (+1 or +2)	Some dose response relationships observed, however not enough studies to confirm this relationship. Insufficient effect size estimates to determine if effect is large or not
	Dose response (+1 or +2)
	No plausible confounding (+1 or +2)

¹Indicates decision. RoB: Risk of Bias. Adapted from Ryan and Hill[21] and Wei et al[22].