Childhood measures of socioeconomic status and cognitive decline in the LifeAfter90 Study

Abstract

AbstractBackgroundChildhood socioeconomic status (SES) is associated with cognitive functioning in adulthood. It is not known if this relationship endures in the oldest old. We examined the associations of subjective and objective childhood SES with baseline cognition and cognitive decline in the LifeAfter90 (LA90) cohort.MethodLA90 is an ongoing diverse cohort of individuals aged 90+ without dementia diagnoses at recruitment. In our analytic sample (n = 341), we operationalized objective childhood SES as maternal education (range 0‐20 years); paternal education was substituted in 14% of cases missing maternal education. Subjective childhood SES was assessed using the MacArthur Scale of Subjective Social Status in which participants ranked their childhood SES using an unnumbered 10‐rung ladder picture (coded continuously with 1 = lowest SES and 10 = highest SES). Executive function (EF), semantic memory (SM), and verbal episodic memory (VEM) were assessed using the Spanish and English Neuropsychological Assessment Scales and z‐standardized to baseline. Mixed effects models estimated the associations between each childhood SES marker and level and change in each cognitive domain, adjusting for baseline age, time since baseline, gender, race and ethnicity, practice effects, and interview mode (phone vs. in‐person). We tested for the association between childhood SES measures and cognitive change by interacting SES measures with time.ResultParticipants completed an average of 3 visits (range 1‐6) each 6 months apart. On average, participants were about 93 years old (SD = 2.2), and 63% were female (Table 1). Mean parental education was 9.8 years (SD = 4.6; range = 0‐20); mean ladder score was 7.1 (SD = 2.4). Higher objective childhood SES was associated with better baseline EF (Figure 1: β = 0.03; 95% CI = 0.02, 0.05) and SM (β = 0.03; 95% CI = 0.02, 0.05). Having higher subjective childhood SES was associated with a slower decline in EF (Table 2: β = 0.02; 95% CI = 0.01, 0.04).ConclusionObjective measures of childhood SES were associated with baseline cognition and subjective childhood SES was associated with slower EF decline among the oldest‐old. High childhood SES may increase chances of surviving past age 90, a selection bias which would attenuate the associations we observed. Our results suggest the long arm of childhood may extend throughout the first century of life.