Table 6.

Summary of findings (SoF) table illustrating the summary on certainty of overall evidence for five outcomes using GRADE

Outcomes	Number of participants (RCTs)	Effect size and 95% CI	Certainty of the evidence (GRADE)a	Comments
Mean Serum hemoglobin	4421 (19)	-0.71 (-1.27 to -0.14)	Moderat	The assessment of certainty by two authors concludes that effect size for the serum hemoglobin is precise and consistent with low risk of bias at outcome level, suggesting that the true effect size for serum hemoglobin is probably close to the estimated effect
Mean Serum Ferritin	3648 (15)	-0.76 (-1.56 to 0.04)	Moderate	The authors believe that effect size for the serum ferritin is precise and consistent with low risk of bias at outcome level, suggesting that the true effect size for serum ferritin is probably close to the estimated effect
Anemia Prevalence	1910 (6)	Could not be estimated	Moderate	While the effect size for anemia could not be calculated, the authors believe that narrative regarding anemia prevalence suggested that anemia declined in the intervention group. Since the evidence was direct, consistent with no risk of bias at the outcome level, the authors believe that certainty of evidence is moderate for the anemia outcome
Mean serum iron levels	677 (4)	Could not be estimated	Low	Since the authors could not estimate the effect size and the findings for iron are from very few studies with inconsistent results, the authors believe that certainty of evidence for iron is low and needs to be explored more in the future
Mean serum transferrin receptor levels	363 (2)	Could not be estimated	Low	Since the authors could not estimate the effect size for the serum transferrin and the findings for serum transferrin are from very few studies with inconsistent results, the authors believe that certainty of evidence for serum transferrin is low and needs to be explored more in the future

Very low: The truth or true effect size is totally different from the estimated effect size

Low: The true effect may be markedly different from the estimated effect size

Moderate: The authors believe that the truth or true effect size is probably close to the estimated effect size

High: The authors’ confidence is high, and they believe that the truth or true effect size is very similar to the estimated effect size

^aGRADE certainty ratings