Life-course socio-economic disadvantage and late-life cognitive functioning in Taiwan: results from a national cohort study.

BACKGROUND

Declines in late-life cognitive functioning differ greatly between socio-economic status (SES) groups, but little is known about whether these effects are related to child and adult SES versus SES effects that accumulate over the individual's life course.

METHODS

An 18-year longitudinal national sample of older adults from Taiwan (n=2944) was used to estimate the effect of socio-economic disadvantage over the individual's life course on cognitive functioning during late life. Cognitive functioning was assessed using the brief Short Portable Mental Status Questionnaire scale. Life-course socio-economic disadvantage, as accrued during childhood and adulthood, included measures of paternal education and occupation and participant's education and occupation.

RESULTS

Multivariate analyses using various mixed-effects models showed that the effects of childhood SES could be largely explained by adult SES and that disadvantageous SES in adulthood further exacerbated declines in late-life cognitive functioning (β=-0.02; p<0.001), even controlling for aging, practice and other covariates. Possible factors that are associated with life-course socio-economic disadvantage and late-life cognitive decline included household income and perception of economic strain.

CONCLUSIONS

The results suggest a critical role for life-course socio-economic disadvantage in late-life cognitive decline and that this may be manifested via the inequitable distribution of socio-economic resources over the individual's life course.