Estimating Sickle Cell Disease Child Mortality from the 2018 Nigeria Demographic and Health Survey

Background: Sickle cell disease (SCD) child mortality in sub-Saharan Africa (SSA) is presumably high but not well-quantified. This contributes to the neglect of SCD and delays the prioritization of interventions. Nigeria has the world’s largest SCD population. Methods: We used Nigeria’s 2018 Demographic and Health Survey (DHS) data to estimate prevalence and geographic distribution of HbSS and HbSC genotypes. We developed a novel approach for estimating SCD child mortality, combining information on tested children (n=10195) and their untested siblings (n=17205). Mortality differences were decomposed using the inheritance-derived genotypic distribution of untested siblings older than the tested cohort, enabling us to estimate excess SCD mortality for the older-sibling cohort (i.e., born between 2003 and 2013, n=15227). Findings: The average birth prevalence of HbSS and HbSC in Nigeria was 1.20% (95% CI: 1.11-1.32%) and 0.23% (95% CI: 0.18-0.28%), respectively. Children born during 2003-2013 with at least one younger sibling in the survey with SCD suffered about 99 (95% CI: 55,144) excess deaths per 1,000 live births, compared with children whose tested siblings were all HbAA. After decomposition, we estimate that children born in 2003-2013 with SCD suffered 480 (95% CI: 270,700) deaths per 1000 live births, 4.0 times (95%CI: 2.1-6.0) higher than comparable children with HbAA. About 4.2% (95%CI: 1.6%-6.8%) of national U5M was attributable to excess SCD mortality. Interpretation: SCD child mortality burden in Nigeria continues to be disproportionately high. The vast majority of these deaths could be prevented if available focused interventions were implemented. The methodology developed here can be used to estimate the burden elsewhere in Africa and South Asia. Funding Statement: APO and DLC are employees of the Bill & Melinda Gates Foundation; OEN is the Nigeria PI of the Sickle Pan African Research Consortium (NHLBI Grant No 1U24HL135881). Declaration of Interests: FBP declares personal fees from Bluebird Bio, outside of the submitted work. All other authors declare no competing interests.