Public Health

Economic hardship has led many Brazilians to enter the workforce prior to age 16. While early employment often limits formal education, its direct impact on late-life cognition remains unclear. Employment may also provide cognitive stimulation that benefits late-life cognition. We examined associations between age of first employment and late-life cognitive function in a national cohort of Brazilians.

In the Brazilian Longitudinal Study of Aging (ELSI-Br), temporal orientation, memory, and verbal fluency were assessed. Orientation was modeled as a raw score (0-4) due to a ceiling effect in the measure (strong left-skewed distribution). Memory and verbal fluency z-scores were standardized by age and sex by subtracting the mean and dividing by the standard deviation within each age and sex group of the full ELSI-Br sample. Age at work initiation was categorized as ≤10 years, 11-15 years, and ≥16 years. Linear regression models estimated associations between early work initiation and cognitive scores, adjusting for race, rural residence, and both mother's and father's education.

Among complete cases (n = 6,488), 41.74% started working at or before age 10, 32.78% between 11-15 years, and 25.48% at age 16 or older (Table 1). In fully adjusted linear models, orientation scores trended higher among those who started working at ages 11-15 (β=0.01 [95% CI=-0.04, 0.07]) and were significantly higher among those who started working after age 16 (β=0.08 [95% CI=0.03, 0.14]) compared to those who initiated employment at age 10 or younger (ref.). Memory scores were significantly higher among those who initiated employment at ages 11-15 (β=0.8 [95% CI=0.02, 0.14) and after age 16 (β=0.17 [95% CI=0.09, 0.25]) compared to the reference. Verbal fluency scores trended slightly lower among those who initiated employment at ages 11-15 (β=-0.02 [95% CI = -0.11, 0.58]) and trended higher among those who started work after age 16 (β=0.08 [95% CI = -0.03, 0.18]) compared to the reference.

These findings highlight the association between early workforce entry and late-life cognition and can inform policies promoting education and delayed employment in vulnerable populations. Future work will explore education and employment as mediators.