Adaptive Functioning in Children and Adolescents With Sickle Cell Disease

Objective: Risk for neurocognitive deficits in sickle cell disease (SCD) is well established, yet minimal research has evaluated the risk for deficits in adaptive functioning. We assessed adaptive functioning in pediatric patients with SCD to test the hypothesis that disease, treatment, and demographic factors were associated with adaptive outcomes.

Methods: Two hundred fifty-six patients (57% HbSS/HbSß0-thalassemia and 43% HbSC/HbSß+-thalassemia), ages 8-18, received routine neuropsychological assessments as part of a larger prospective lifetime cohort study. Adaptive functioning was measured using the Behavior Assessment System for Children, Second or Third Edition. Adaptive scores were compared with normative values using t-test or Wilcoxon signed rank test and linear regression models were used to measure associations between adaptive functioning and age, hydroxyurea (HU) use, sickle genotype, and socioeconomic status. Furthermore, we examined the influence of intellectual and executive functioning on adaptive behavior using hierarchical linear regression analyses.

Results: Parent ratings of adaptive functioning skills did not differ from normative expectations (all false discovery rate [FDR] adjusted p-value [pFDR] > 0.05). Social vulnerability was negatively associated with adaptive scores on most adaptive scales in both genotypes (pFDR < 0.05). HU treatment was not significantly associated with any adaptive scale. Overall IQ was positively associated with Functional Communication and Leadership only for those with HbSS/HbSß0-thalassemia. Higher parent ratings of executive difficulties were correlated with lower adaptive scores (estimate = -0.64, standard error = 0.051, p < .001).

Conclusions: Poorer parent-rated adaptive skills were associated with increased social vulnerability, lower Full-Scale IQ, and parent-rated executive difficulties. Most adaptive scores were in the normal range; however, parent ratings may not fully capture the impact of disease complications and neurocognitive deficits on daily functioning.