Social determinants of cognitive outcomes in survivors of pediatric brain tumors treated with conformal radiation therapy

Background Social determinants of health including parental occupation, household income, and neighborhood environment are predictors of cognitive outcomes among healthy and ill children; however, few pediatric oncology studies have investigated this relationship. This study utilized the Economic Hardship Index (EHI) to measure neighborhood-level social and economic conditions to predict cognitive outcomes among children treated for brain tumors (BT) with conformal radiation therapy (RT). Methods Two hundred and forty-one children treated on a prospective, longitudinal, phase II trial of conformal photon RT (54-59.4 Gy) for ependymoma, low-grade glioma, or craniopharyngioma (52% female, 79% white, age at RT = 7.76 +/- 4.98 years) completed serial cognitive assessments (intelligence quotient [IQ], reading, math, and adaptive functioning) for ten years. Six US census tract-level EHI scores were calculated for an overall EHI score: unemployment, dependency, education, income, crowded housing, and poverty. Established socioeconomic status (SES) measures from the extant literature were also derived. Results Correlations and non-parametric tests revealed EHI variables share modest variance with other SES measures. Income, unemployment, and poverty overlapped most with individual SES measures. Linear mixed models, accounting for sex, age at RT, and tumor location, revealed EHI variables predicted all cognitive variables at baseline and change in IQ and math over time, with EHI overall and poverty most consistent predictors. Higher economic hardship was associated with lower cognitive scores. Conclusions Neighborhood-level measures of socioeconomic conditions can help inform understanding of long-term cognitive and academic outcomes in survivors of pediatric BT. Future investigation of poverty's driving forces and the impact of economic hardship on children with other catastrophic diseases is needed.