Psychosocial work demands and physical workload decrease with ageing in blue-collar and white-collar workers: a prospective study based on the SLOSH cohort

OBJECTIVES: Psychosocial work demands and physical workload are important causes of ill health. The dramatic demographic changes in society make it important to understand if such factors change with ageing, but this is presently not known. The purpose of the present study was to investigate whether psychosocial work demands and physical workload change across 8 years of ageing, whether occupational groups show different trajectories of change and if such trajectories are reflected in sleep or fatigue. METHODS: A cohort of 5377 participants (mean age: 47.6±11.6 (SD) years, 43.2% males, 40.2% blue-collar workers) was measured through self-report in five biannual waves across 8 years. Mixed model regression analyses was used to investigate change across ageing. RESULTS: Psychosocial work demands decreased significantly across 8 years (Coeff: −0.016±0.001), with the strongest decrease in the high white-collar group (Coeff=−0.031±0.003) and the oldest group. Physical workload also decreased significantly (Coeff=−0.032±0.002), particularly in the blue-collar group (Coeff=−0.050±0.004) and in the oldest group. Fatigue decreased, and sleep problems increased with ageing, but with similar slopes in the occupational groups. All effect sizes were small, but extrapolation suggests substantial decreases across a working life career. CONCLUSIONS: The decrease in psychosocial work demands and physical workload suggests that the burden of work becomes somewhat lighter over 8 years. The mechanism could be ‘pure’ ageing and/or increased experience or related factors. The gradual improvement in the work situation should be considered in the discussion of the place of older individuals in the labour market, and of a suitable age for retirement. The results also mean that prospective studies of work and health need to consider the improvement in working life with ageing.