Amount of work : studies on premature death and subjective health in a work life balance perspective

The aim of this thesis is to increase knowledge about the association between amount of work and health. Amount of work is measured as unemployment, excessive work, and interference between work and home. Two studies, based on the Swedish Twin Register, consider amount of work in work-related settings and focus on mortality in both sexes (n=20 632). Two studies take into account demands from both professional and domestic settings and consider their impact on subjective health (n=6 800 ).

Unemployment had a strong effect on suicide among women and on death by external undetermined causes among men. For women, the relationship was strengthened by use of sleeping pills and tranquillizers as well as by personality. For men, this applied to low level of education, long-term illness and use of sleeping pills. Overtime work and 'extra work' were both associated with premature death among women. Among men, this applied only to 'extra work'. Working 1-5 hours' overtime per week was related to a reduced risk of premature death among men.

Work-home interference was associated with impaired sleep quality and suboptimal self-rated health. These associations disappeared among women, but not among men, when adjusted for lack of unwinding. Parttime work lowered the odds for suboptimal subjective health. Only among fulltime working men was an association observed for use of medication. Home-work interference was associated with impaired sleep quality and suboptimal self-rated health among full-time but not part-time workers. The associations with sleep quality, but not those with self-rated health, disappeared when adjusted for lack of unwinding.

Working women experienced interference arising from both professional and domestic settings simultaneously and they also lack unwinding. Women with qualified, demanding and time-inflexible work constituted a high-risk group since they had the most significant excessive odds of suboptimal self-rated health that remained when lack of unwinding was controlled for. In the absence of a work-life balance, unhealthy stress may arise, and health may be threatened. The health outcomes encountered in this thesis can partly be explained by a long lasting activation of the body's stress systems. Physiological activation, allostatic load, is here considered in its role as a link between amount of work and health.

List of scientific papers

I. Voss M, Nylen L, Floderus B, Diderichsen F, Terry PD (2004). Unemployment and early cause-specific mortality: a study based on the Swedish twin registry. Am J Public Health. 94(12): 2155-61.
https://pubmed.ncbi.nlm.nih.gov/15569968

II. Nylen L, Voss M, Floderus B (2001). Mortality among women and men relative to unemployment, part time work, overtime work, and extra work: a study based on data from the Swedish twin registry. Occup Environ Med. 58(1): 52-7.
https://pubmed.ncbi.nlm.nih.gov/11119635

III. Nylén L, Melin B, Laflamme L (2006). Interference between work and outside work demands relative to health, unwinding possibilities among full-time and part-time employees. [Submitted]

IV. Nylén L, Melin B, Laflamme L (2006). Interplay between sources of interference, unwinding, work characteristics and health - a study among working women. [Submitted]