Background: Inappropriate feeding practices among infants and young children are adversely associated with their growth and development. This study aimed to investigate the causal association between appropriate complementary feeding and child growth among children aged 6 to 23 months in Malawi using propensity score matching.
Methods: Data on 4722 children aged 6 to 23 months from the 2015-16 Malawi Demographic and Health Survey (MDHS) were analysed. Distribution of confounder variables on children who were not on appropriate complementary feeding were made similar to those who were on appropriate complementary feeding using a 1:1 nearest neighbour matching within a calliper region of 0.1. Matching was evaluated based on the average standardised absolute mean differences and covariate specific p-values after matching. The effect of appropriate complementary feeding was estimated based on the matched sample. A sensitivity analysis was done to assess the effect of unmeasured confounders on the estimates.
Results: The prevalence of stunting was at 28% (95% CI:27%,29%), wasting was at 3.3%(95% CI:2.5%,4.1%) and underweight was at 13.6%(95% CI:12.1%,15%). Of the 4772 children, 16.7% (95% CI:15.6, 17.8) were given appropriate complementary feeding. A majority (81.8%) of the children were initiated to complementary feeding after 6 months of age. Appropriate complementary feeding was associated with reduced stunting (OR=0.5, 95% CI:0.3,0.9) among the children but did not have an effect on wasting and underweight.
Conclusion: The study has found that appropriate complementary feeding led to less stunting among children aged 6-23 months in Malawi. The use of statistical techniques such as propensity score matching to balance confounder variables could be useful to reduce bias in the estimation of exposure comparative effectiveness from observational studies. We recommend optimal feeding for young children, especially in resource-limited settings.