Objectives: To investigate the association between job strain and subsequent cognitive change over approximately 11 years, using data from the population-based Baltimore Epidemiologic Catchment Area follow-up study.
Methods: The sample ranged from 555 to 563 participants, depending on the outcome, who reported psychosocial characteristics corresponding to the full-time job they held at baseline (1993-1996). Overall cognitive performance was measured by the Mini-Mental State Examination (MMSE), and verbal memory was measured by the ImmediateWord Recall Task and Delayed Word Recall Task at baseline and follow-up (2004-2005). Multiple linear regression was used to examine the association between job strain and cognitive change, and inverse probability weighting was used to account for differential attrition.
Results: Participants with high job demands (psychological or physical demands) and/or low job control had greater decrease in the MMSE and memory scores than those with low job demands and high job control. After adjustment for baseline outcome scores, age and sex, the greatest decrease was observed in participants with high job demands and low job control (MMSE: -0.24, 95% CI -0.36 to -0.11; verbal memory scores: -0.26, 95% CI -0.44 to -0.07). The differences were partially explained by sociodemographic characteristics, occupational prestige and health factors.
Conclusions: Findings from this prospective study suggest that job strain is associated with and may be a potential modifiable risk factor for adverse cognitive outcomes.
Keywords: ageing; epidemiology; mental health; public health; stress.
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