EVect of change in the psychosocial work environment on sickness absence: a seven year follow up of initially healthy employees

Study objective—To investigate the impact of changes in psychosocial work environment on subsequent sickness absence. Design—Analysis of questionnaire and sickness absence data collected in three time periods: 1990–1991, before the recession; 1993, worst slump during the recession; and 1993–1997, a period after changes. Setting—Raisio, a town in south western Finland, during and after a period of economic decline. Participants—530 municipal employees (138 men, 392 women) working during 1990–1997 who had no medically certified sick leaves in 1991. Mean length of follow up was 6.7 years. Main results—After adjustment for the pre-recession levels, the changes in the job characteristics of the workers during the recession predicted their subsequent sick leaves. Lowered job control caused a 1.30 (95% CI = 1.19, 1.41) times higher risk of sick leave than an increase in job control. The corresponding figures in relation to decreased social support and increased job demands were 1.30 (95% CI = 1.20, 1.41) and 1.10 (95% CI = 1.03, 1.17), respectively. In some cases there was an interaction with socioeconomic status, changes in the job characteristics being stronger predictors of sick leaves for employees with a high income than for the others. The highest risks of sick leave (ranging from 1.40 to 1.90) were associated with combined eVects related to poor levels of and negative changes in job control, job demands and social support. Conclusion—Negative changes in psychosocial work environment have adverse eVects on the health of employees. Those working in an unfavourable psychosocial environment before changes are at greatest risk. (J Epidemiol Community Health 2000;54:484–493) Several studies have demonstrated the association between the level of job characteristics and various aspects of health (for example, cardiovascular mortality and morbidity, sickness absence). Consequently, policy implications of prior studies have included strategies to change the work environment toward a direction in which the level of job characteristics indicates lower health risk. To be precise, however, evidence showing that a change in job characteristics is really followed by a change in health is still sparse. Exposure to job characteristics, such as job control, job demands and social support at work, has been assessed in the studies of Johnson et al and Bosma et al. The first investigation showed that workers with low job control had a significantly higher relative risk for cardiovascular mortality than other workers, and that this risk varied slightly depending on the exposure time. However, workers exposed to both low control and low social support for a long period of time had the highest relative risk. By calculating the mean from the levels of job characteristics obtained on two occasions, Bosma et al showed that the participants with high levels of control at both phases were at a lower risk of self reported disease than those having low job control on both occasions. The risk of disease in the intermediate exposure group was between those found in the two above mentioned groups. The intermediate group included participants with stable intermediate job control and those who changed from low to high job control, as well as those who changed from high to low job control between the phases. Instead of exposure, Theorell et al focused on changes in the psychosocial work environment by comparing the levels of job characteristics 10 years before and one year before the first myocardial infarction in a casereferent study. A decrease in job control during the 10 years preceding the infarction, as indicated by a transition to a lower job status, was associated with increased risk after adjustments for demographic, biological and behavioural risk factors. Corresponding results were not obtained in relation to job