Multi-cohort study links job demands and sociodemographics to mortality and wellbeing

Dr. Prakash K.C. examined the impact of physical job demands on changes in self-rated health over time. Self-rated health is a subjective measurement of health where a research participant is asked to rate their own health on a given scale. For instance, the scale can range from ‘good’ and ‘average’ to ‘suboptimal’. 

In Dr. K.C.’s study, people who experienced high physical job demands were 18% more likely to change the ratings of their own health from ‘good’ to ‘suboptimal’ as they aged compared with people who had less physically demanding jobs. Likewise, people who rated their health as ‘suboptimal’ in midlife were 52% more likely to maintain this perception of poor health years later if their work had been physically demanding.

Ms. Kamilia Tanjung’s research is on the relationship between physical job demands and all-cause mortality. Her study suggests that both men and women with moderate to high levels of physical work demands are more likely to die at relatively younger ages than their peers with low physical demands. 

The most robust association in Tanjung’s study was found among men with physically moderate work, where the risk of death was 10%. Additionally, previous studies that have examined the same topic have yet to determine whether physical job demands could be just as detrimental for women’s survival in older age. However, the current study was able to show a negative impact on women. 

Despite growing digitalisation work remains physical 

Dr. K.C.’s and Ms. Tanjung’s findings are aligned with the health paradox theory. The theory indicates that while physical activity generally promotes an individual’s health, the health advantage seems to occur only in specific domains of life, such as leisure time, during daily activities and commuting. Occupational physical activity, however, is one domain of life where the well-known health benefits of physical activity do not seem to persist.

“Our findings could explain the inequalities in health and life expectancy that are observed worldwide. Physical job demands involve activities such as heavy lifting, carrying or pushing large objects and prolonged physical movements. These activities make up most of the tasks of lower grade or blue-collar occupations,” K.C. and Tanjung say. 

Despite the growing trends of digitalisation and automation at work, jobs with moderate to high degrees of physical requirements remain the most common occupation for many people across the globe, including those in the most developed countries. 

“Therefore, it is possible that the differences in overall health status within a country’s population are the result of exposure to heavy physical work,” K.C. and Tanjung state.

The conclusions of these studies were drawn from four existing longitudinal cohort studies on ageing in Finland, United Kingdom, France and the US. The number of participants included in the analyses ranged between 35,000 and 40,000 participants and they had been traced for over 25 years. Both studies utilised a novel two-stage individual participant data meta-analysis approach to address the research questions in the respective studies. 

Reference to original studies and links to full texts

1. Prakash KC, Stenholm S, Kyrönlahti S, Kulmala J, Tanjung K, Nosraty L, Leino-Arjas P, Goldberg M, Nygård CH, Kivimäki M, Neupane S. Sociodemographic and work-related determinants of self-rated health trajectories: a collaborative meta-analysis of cohort studies from Europe and the US. Scientific Reports. 2025 Feb 13;15(1):5394.
2. Tanjung K, KC P, Kyrönlahti S, Goldberg M, Nygård CH, Neupane S. Associations of psychosocial and physical work demands with all-cause mortality: a pooled analysis of prospective cohort studies. International Journal of Epidemiology. 2025 Jun;54(3):dyaf045. 
    

Photo: Jonne Renvall /Tampere University