Summary of findings for the main comparison. Summary of findings table 1.

Intermittent preventive treatment compared to placebo for children with anaemia
Patient or population: Children with anaemia Settings: Malaria‐endemic areas Intervention: IPT (± iron and folic acid) Comparison: Placebo (± iron and folic acid)
Outcomes	Illustrative comparative risks* (95% CI)		Relative effect (95% CI)	No of participants (trials)	Quality of the evidence (GRADE)
	Assumed risk	Corresponding risk
	Placebo	IPT
Death or hospital admission Follow up at 6 months	34 per 1000	31 per 1000 (24 to 38)	RR 0.9 (0.71 to 1.13)	3160 (3 trials)	⊕⊕⊕⊝ moderate1,2,3,4
Children with anaemia (Hb < 11 g/dL) Follow up at 12 weeks	579 per 1000	561 per 1000 (510 to 620)	RR 0.97 (0.88 to 1.07)	2237 (4 trials)	⊕⊕⊕⊝ moderate2,5,6,7
Mean change in Hb from baseline Follow up: 12 weeks	The mean change ranged across control groups from 0.32 to 5.4 g/dL	The mean change in the intervention groups was 0.32 g/dL higher (0.19 to 0.45 higher)	‐	1672 (4 trials)	⊕⊕⊕⊝ moderate2,8,9,10
Mean Hb Follow up at 12 weeks	The mean Hb concentration ranged across control groups from 9.91 to 10.7 g/dL	The mean Hb concentration in the intervention groups was 0.35 g/dL higher (0.06 to 0.64 higher)	‐	1672 (4 trials)	⊕⊕⊝⊝ low8,9,10,11
*The basis for the assumed risk is the median control group risk across trials. The corresponding risk (and its 95% CI) is based on the assumed risk in the comparison group and the relative effect of the intervention (and its 95% CI). CI: Confidence interval; RR: Risk ratio; IPT: intermittent preventive treatment; AL: artemether lumefantrine.
GRADE Working Group grades of evidence High quality: Further research is very unlikely to change our confidence in the estimate of effect. Moderate quality: Further research is likely to have an important impact on our confidence in the estimate of effect and may change the estimate. Low quality: Further research is very likely to have an important impact on our confidence in the estimate of effect and is likely to change the estimate. Very low quality: We are very uncertain about the estimate.

¹ No serious risk of bias: The largest trial was at low risk of bias. The two smaller trials were at high risk of attrition bias, but exclusion of these trials does not change the result.
 ² No serious inconsistency: Statistical heterogeneity was low.
 ³ No serious indirectness: The three trials were conducted in the Gambia, Kenya and Malawi, one trial gave IPT (AL monthly) to children discharged from hospital following severe malarial anaemia, and two trials gave IPT (SP monthly) to anaemic children attending hospital, outpatient clinics or recruited in the community. There was no significant result for subgroup differences between areas with high versus areas with low endemicity.
 ⁴ Downgraded by 1 for serious imprecision: The 95% CI around the absolute risk difference is very narrow and excludes clinically important effects. However, much larger trials would be necessary to fully exclude small benefits with IPT.
 ⁵ Downgraded by 1 for serious risk of bias: high risk of attrition bias for Bojang 2010 GMB and Desai 2003 KEN.
 ⁶ No serious indirectness: All the trials gave IPT (SP) monthly to anaemic children attending hospital, outpatient clinics or recruited in the community. There was no significant result for subgroup differences between areas with high versus areas with low endemicity.
 ⁷ No serious imprecision: No effect was seen and the meta‐analysis is adequately powered to detect an effect.

⁸ No serious imprecision. A small effect was seen although this disappears when we removed trials at high risk of bias from the analysis.
 ⁹ Downgraded by 1 for serious risk of bias: High risk for attrition bias for Bojang 2010 GMB and Desai 2003 KEN.
 ¹⁰ No serious indirectness: Three trials gave IPT (SP) monthly and one trial gave CQ weekly to anaemic children attending hospital, outpatient clinics or recruited in the community. There was no significant result for subgroup differences between areas with high versus areas with low endemicity.
 ¹¹ Downgraded for serious inconsistency: Heterogeneity (I² statistic = 76%; Chi² statistic = 16.93; P = 0.002) is present. One trial is an outlier (Desai 2003 KEN).