Social determinants of neurocognitive and academic performance in sickle cell disease

Abstract

Background: Sickle cell disease (SCD) is associated with poor neurocognitive outcomes due to biomedical and psychosocial factors. The aims of this study were to investigate associations between household and neighborhood socioeconomic status (SES) with cognitive and academic outcomes in SCD and to determine if these relationships were modified by sickle genotype, fetal hemoglobin, or age.

Procedure: We prospectively recruited patients to complete a battery of neurocognitive and academic measures. Household SES was measured using the Barratt Simplified Measure of Social Status, a composite index of parent education and occupation. The Social Vulnerability Index was used to classify individuals based on social vulnerabilities at the neighborhood level.

Results: Overall, 299 patients between the ages of 4 and 18 (mean = 11.4, standard deviation = 4.3) years diagnosed with SCD (57% SS/SB⁰ -thalassemia) completed testing. Stepwise multivariate models demonstrated that patients with low social vulnerability (i.e., high SES) at the neighborhood level displayed intelligence and math scores that were 4.70 and 7.64 points higher than those living in areas with moderate social vulnerability, respectively (p < .05). Reading performance did not differ based on neighborhood SES; however, the effect of neighborhood SES was dependent on age, such that older participants living in neighborhoods with moderate or high levels of social vulnerability displayed poorer reading scores than those with low social vulnerability (p < .05).

Conclusions: This study identified patients with SCD at higher risk of poor academic performance based on SES. Interventions addressing academic difficulties should be offered to all children with SCD, but should be emergently offered to this subpopulation.

Keywords: academic; anemia; neurocognitive; sickle cell; social determinant; socioeconomic status.

Figure 1.. Interaction between age and social vulnerability on reading performance in patients with sickle cell disease

SVI, Social Vulnerability Index. Age displayed in years. HbSS/HbSb0-thalassemia, sickle cell anemia; HbSC/Hb Sβ+-thalassemia, hemoglobinopathy. Social Vulnerability Index categorized as low= 0–33, moderate = 33–66, high = 66–100. The Wechsler Abbreviated Scale of Intelligence-Second Edition (WASI-II) provided an estimated Full-Scale Intelligence Quotient (4-subtest; Full Scale IQ). Academic achievement was measured using Letter-Word Identification and Math Fluency from the Woodcock-Johnson Test of Achievement – Third Edition. p-value was calculated using multivariate linear regression model with adjusting for BSMSS, SCD genotype, age at evaluation, categorical SVI, interactions between categorical SVI and age and between categorical SVI and SCD genotype.