Why was this study done?
When workers have less ability to make decisions about the way they work or use their skills – which is known as low job control – then they are more likely to have poorer health. However, because people with low job control may also experience other factors related to poor health, such as poor living conditions and low income, questions remain as to whether having low job control independently causes poor health. This study examined different ways by which job control affects health and explored whether these pathways were independent of other factors such as household income and neighbourhood stress.
How was the study done?
Researchers examined job control in relation to workers’ self-rated health, psychological distress and health behaviours such as smoking and physical activity in 3,411 workers aged 25 to 60 from the Canadian National Population Health Survey. They also considered the effects of education, chronic stress and level of household income.
What did the researchers find?
For workers with low job control in 1994, there was a direct effect on lower self-reported health in 2002. There was also an indirect link, as these workers had lower physical activity levels in 1996. When researchers accounted for other factors that could contribute to these effects -- such as personal stress levels or household income -- the relationship between job control and health did not change significantly. However, low job control, high environmental stress and low household income did have a cumulative effect on both physical activity and health status.
What are some strengths and weaknesses of the study?
The large sample represents Canadian workers well. Also, the researchers were able to include several different exposures to stress inside and outside of work. This allowed them to examine different ways by which job control was associated with lower health status. However, all measures were based on self-reports, so the associations could have been overstated.