Summary of findings 4. Nutrition systems strengthening interventions targeting children compared with no intervention or standard care to reduce stunting (height‐for‐age, length at 18 months).

Nutrition systems strengthening interventions targeting children compared with no intervention or standard care to reduce stunting (height‐for‐age, length at 18 months)
Patient or population: children under 5 years old Settings: poor urban slums Intervention: nutrition systems strengthening Comparison: no intervention or standard care
Outcomes	Relative effect (95% CI)	No of participants (studies)	Certainty of the evidence (GRADE)	Comments
Nutrition support vs no intervention
Height‐for‐age (z‐score) at 18 months	Effect: MD 0.386 (0.209 to 0.562) unadjusted difference; MD 0.272 (0.099 to 0.445) adjusted for socioeconomic status, hygiene score, and birth weight variables	377 (1)	⊕⊕⊝⊝ Lowa	Penny 2005
Height‐for‐age (z‐score)	Unclear effect: intervention (2013 boys –1.33, 2013 girls 1.41; 2011 boys –1.69, 2011 girls –1.46) control (2013 boys –1.27, 2013 girls 1.28; 2011 boys –1.65, 2011 girls –1.49)	999 (1)	⊕⊝⊝⊝ Very lowb	Pridmore 2014
Length (cm) at 18 months	Effect: MD 1.068 (0.488 to 1.648) unadjusted difference; MD 0.714 (0.146 to 1.282) adjusted for socioeconomic status, hygiene score, and birth weight variables	377 (1)	⊕⊕⊝⊝ Lowc	Penny 2005
CI: confidence interval; MD: mean difference. GRADE Working Group grades of evidence High certainty: further research is very unlikely to change our confidence in the estimate of effect. Moderate certainty: further research is likely to have an important impact on our confidence in the estimate of effect and may change the estimate. Low certainty: 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 certainty: we are very uncertain about the estimate.

^aThe overall risk of bias was high and, as it was a systems strengthening intervention, it was not possible to blind allocation. We downgraded two levels for bias and indirectness of evidence (geographical coverage). Refer to Appendix 14 for more details. Therefore, the overall GRADE was low.
 ^bThe overall risk of bias was high because this was not a randomised controlled trial (downgraded one level). We started GRADE assessment at low because this is not an RCT. We downgraded two levels for bias and indirectness of evidence (geographical coverage). Refer to Appendix 14 for more details. Therefore, the overall GRADE was very low.
 ^cThe risk of bias was high and as it was a systems strengthening intervention it was not possible to blind allocation. We downgraded two levels for bias and indirectness of evidence (geographical coverage). Refer to Appendix 14 for more details. Therefore, the overall GRADE was low.