Estimating Causal Effects of Malaria Infection on Anaemia Among Children Under Five Years in Uganda: Evidence From a Cross-Sectional Malaria Indicator Survey.

Background and Aims: Malaria and anemia remain major public health challenges contributing substantially to morbidity and mortality among children under 5 years in sub-Saharan Africa (SSA). Although conventional regression analyses have reported a significant association between malaria infection and anemia, these approaches often inadequately account for socioeconomic and demographic confounders, thereby limiting causal interpretation. This study aimed to estimate the causal effect of malaria infection on anemia among children under five in Uganda using a robust quasi-experimental approach. Methods: We conducted a Propensity Score Matched (PSM) analysis using data from the 2018-2019 Uganda Malaria Indicator (Cross-Sectional) Survey (UMIS). The study population comprised children under 5 years of age with complete data on malaria status (exposure) and anemia status (outcome). A logistic regression model was used to estimate the propensity scores, incorporating a comprehensive set of child-level, maternal, and contextual covariates. The Average Treatment Effect on the Treated (ATT) was estimated in Stata v14.0 using survey weights to account for the UMIS complex sampling design. Result: The prevalence of malaria infection among children under five was 23.6% [95% CI: 19.8, 27.8], while the prevalence of anaemia (mild, moderate, or severe) was 51.2% [95% CI: 48.3, 54.1]. The effect of exposure to malaria infection on anaemia was positive and significant [Average Treatment Effect of the Treated (ATT) = 25.6%, 95% CI: 17.6%, 33.5%, Conclusion: Malaria infection is a major driver of anaemia among Ugandan children under five. Strengthening malaria prevention and prompt treatment could substantially reduce childhood anemia and its associated health burden.