Abstract Background: Sickle cell disease (SCD) significantly contributes to under-five morbidity and mortality in sub-Saharan Africa and increases vulnerability to undernutrition. However, limited studies exist on the prevalence of undernutrition and its associated factors among children under five years with SCD in Uganda. We assessed the prevalence of undernutrition and its associated factors among children with SCD aged 6-59 months attending the sickle cell clinic at Mulago National Referral Hospital in Kampala, Uganda. Methods: A facility-based cross-sectional study was conducted among 329 children aged 6-59 months. Data was collected in August 2022 using a structured questionnaire and analyzed using STATA version 14.0. Modified Poisson regression was used to identify the factors associated with undernutrition. Results: The prevalence of undernutrition among children with SCD aged 6-59 months was 31.3% (n=103) 95% CI 26.5, 36.5; 27.4% (n=90) 95% CI 22.8, 32.5 were stunted, and 14.3% (n=47) 95% CI 10.8, 18.5 were underweight. Undernutrition among children with SCD was statistically significantly associated with children below 24 months but not breastfeeding (aPR=1.27; 95% CI: 1.09-1.48; P-0.002), not immunized against measles (aPR=1.31; 95% CI: 1.02-1.68; P-0.03), and child not taking hydroxyurea drug (aPR=1.5; 95% CI: 1.07-2.08; P-0.017). Conclusion: Early weaning of children, not being immunized against measles, and the child not taking hydroxyurea drug were great contributors to undernutrition. There is a need for sensitization of the caretakers about these predictors, and integrating hydroxyurea treatment in the standard care package of management of SCD in Uganda.

The authors have declared no competing interest.

The author(s) received no specific funding for this work.

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