Supplementary Material for: Prevalence of Sickle Cell Trait and Reliability of Self-Reported Status among Expectant Parents in Nigeria: Implications for Targeted Newborn Screening

Background/Aims: Sickle cell disease (SCD) is a life-threatening, autosomal recessive blood disorder prevalent in sub-Saharan Africa. We identified the prevalence of sickle cell trait (SCT) among pregnant women and their male partners in Enugu State, Nigeria, and determined the accuracy of self-reported sickle cell status and its reliability for identifying high-risk newborns for targeted screening. Methods: We conducted a nested cohort study of expectant parents enrolled in the Healthy Beginning Initiative (HBI). The HBI is a cluster-randomized trial of a congregation-based approach designed to increase HIV testing. Participants completed a survey regarding self-awareness of their sickle cell genotype and consented to genotype screening by cellulose acetate electrophoresis. Results: SCT prevalence (HbAS) was 22% (746/3,371). Only 50% of participants provided an accurate self-report. Self-report accuracy was significantly different (p < 0.0001) between individuals who reported having SCT or SCD (61% accuracy) versus those who reported not having SCT or SCD (86% accuracy). Demographic variables including gender, age, household size, employment, education, and home location were significantly associated with providing an accurate self-report. Conclusions: Low numbers of accurate parental self-reports, coupled with a high SCT prevalence in Nigeria, could limit the efficacy of targeted newborn screening. However, our data indicate that it is feasible to integrate sickle cell screening for pregnant women with existing, community-based health care programs developed by the President's Emergency Plan for AIDS Relief (PEPFAR), such as the HBI. Expanding screening programs could enable the development of targeted newborn screening based on maternal genotype that could identify all newborns with SCD in resource-limited settings.