Abstract

Introduction: Broad neurocognitive deficits have been documented in children with sickle cell disease (SCD), even in the absence of stroke. These deficits pose significant consequences, as lower cognitive abilities are associated with lower academic achievement. However, there has been limited research examining the relationship between neurocognitive functioning and socioeconomic status (SES) in youth with SCD. Given that children with SCD experience socioeconomic disadvantage at relatively high rates, SES has been posited as one explanation for the high prevalence of neurocognitive issues in SCD; particularly in the case of patients without stroke or those with less severe phenotypes. In order to better understand the role of SES, we sought to evaluate the effects of multiple distinct measures of SES on neurocognitive outcomes in pediatric SCD.

Methods: Fifty-nine children with SCD ages 7-16 (M = 10.44, SD = 2.87; 42% male) enrolled in a larger study of the feasibility and efficacy of a computerized cognitive training program. Primary caregivers reported demographic information, including the child's age, gender, and ethnicity, and rated their child's executive functioning difficulties on the Behavior Rating Inventory of Executive Function (BRIEF). Scores on the BRIEF are represented as T scores, where higher scores reflect more problems. Caregivers also reported on multiple measures of SES, including the participant's health insurance type, whether the participant received free-or-reduced lunch at school, and rated the adequacy of household resources (Family Resource Scale; FRS) and their perceived community and national social status (The MacArthur Scale of Subjective Social Status). Children and adolescents completed the Wechsler Intelligence Scale for Children, Fifth Edition (WISC-V).

Results: Multiple regression analyses were performed to examine the relationship between SES measures and performance-based and caregiver-reported neurocognitive and behavioral functioning. Controlling for age and gender, having public health insurance significantly predicted lower Full Scale IQs on the WISC-V (R2 = .158, b = -8.609, p = .021), as well as greater impairments on the BRIEF Working Memory (R2 = .219, b = -9.556, p = .014), Organization of Materials (R2 = .166, b = -7.498, p = .011), and Monitor (R2 = .137, b = -6.872, p = .038) subscales. Whereas, having private health insurance significantly predicted higher Full Scale IQs (R2 = .187, b = 10.376, p = 0.007) and fewer problems on the BRIEF Working Memory (R2 = .101, b = 7.868, p = .046), Organization of Materials (R2 = 0.209, b = 9.103, p = .003), and Monitor (R2 = .163, b = 8.231, p = .018) subscales. Additionally, receiving free-or-reduced lunch significantly predicted lower scores on a WISC-V task measuring processing speed (R2 = .316, b = -1.976, p = .006) and a composite indicator of processing speed (R2 = .226, b = -9.849, p = .011). In contrast to hypotheses, higher perceived social status within families' communities on the MacArthur Scale of Subjective Social Status was predictive of lower Full Scale IQs (R2 = .089, b = 1.646, p = .049) and higher perceived social status using the United States as a reference predicted greater impairments on the Plan/Organize (R2 = .169, b = 2.287 p = .011) and Initiate subscales of the BRIEF (R2 = .134, b = 1.839, p = .024).

Conclusions: It is feasible to measure SES in multiple ways in clinical trials. In our study, SES significantly predicted performance-based and parent-reported neurocognitive functioning; however, each measure of SES appeared to account for a unique component of SES and demonstrated unique associations with neurocognitive outcomes. Public insurance was a significant predictor of more caregiver-rated problems with children's working memory, organizational skills, and executive functioning. Children who qualified for free-or reduced lunch also scored significantly lower on processing speed tasks. Findings support the hypothesis that SES plays an important role in determining neurocognitive and behavioral outcomes and highlights the value of conceptualizing and assessing SES as a multidimensional construct. Researchers and clinicians should routinely assess SES using various measures to enhance detection of neurocognitive difficulties and assist in crafting tailored interventions to mitigate negative consequences of low SES in children with SCD.

Disclosures

No relevant conflicts of interest to declare.

Author notes

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Asterisk with author names denotes non-ASH members.