Socioeconomic status and longitudinal neurocognitive outcomes following childhood brain tumour diagnosis: a Swedish national population-based cohort study

Abstract Background Lower socioeconomic status (SES) is linked to poorer neurocognitive development in the general population, but these effects in paediatric brain tumour survivors are underexplored. We examined the relationship between parental SES, clinical factors, and neurocognitive functioning longitudinally up to five years post-diagnosis and determined if young children were more vulnerable. Methods This population-based registry study included Swedish children diagnosed with brain tumours between 2008-2023 and who completed ≥2 neurocognitive assessments. Parental education, occupation and household income were used as individual SES indicators as well as a combined SES measure. Linear mixed models examined relationships between SES and age at diagnosis on neurocognitive outcomes, accounting for time since diagnosis, chemotherapy, and radiotherapy. Results We included 461 children (mean age at diagnosis=7.98 years, SD=4.01). Higher SES was associated with higher neurocognitive z-scores on processing speed (B=0.23), working memory (B=0.25), nonverbal reasoning (B=0.29), verbal reasoning (B=0.41), and global cognition (B=0.42; q’s≤ .039). No interactions between SES and age or time were observed. Longer time since diagnosis was associated with lower processing speed (B=-0.04) and verbal reasoning (B=-0.05, q’s≤.041). Younger age at diagnosis was related to steeper declines in nonverbal reasoning (B=0.01, q=.016). Cranio-spinal irradiation was related to lower processing speed (B=-0.50, q=.019). Conclusions In Swedish childhood brain tumour survivors, lower SES was associated with poorer neurocognitive functioning over time. Absence of socioeconomic differences in rate of decline suggests that lower SES may reduce baseline cognitive reserve rather than amplifying disease or treatment-related toxicity.