Objectives: We used data from SWEOLD, a Swedish nationally representative study of individuals aged 77 years or older, to examine midlife indicators of job strain in relation to cognitive performance and impairment.
Methods: In all, 827 participants completed an abridged 11-point version of the Mini-Mental State Examination in-person in 1992 and/or 2002 and had self-reported and/or occupation-based scores for job control and demands from data collected in 1968. Seventeen percent scored below the cutoff for cognitive impairment.
Results: Controlling for age, sex, education, self-rated health, and year of cognitive screening, low self-reported and occupation-based job control at midlife was associated with poorer cognitive performance later (ps < .001). For the occupation-based measure, low job control was also associated with greater likelihood of impairment, whereas having an active job (high job control/high job demands) was associated with better cognitive performance and lower likelihood of impairment (ps < .01). Childhood environment, midlife depressive symptoms, and social activity had limited influence, whereas the influence of both adulthood socioeconomic position and work complexity on these results was more pronounced.
Discussion: Job control at midlife, by itself and in combination with job demands, may influence cognitive functioning later above and beyond demographic variables and other occupational characteristics.