Workplace as an origin of health inequalities.

OBJECTIVE To investigate the effect of the workplace on the socioeconomic gradient of sickness absence. DESIGN Comparison of the relation between socioeconomic status and employee sickness absence in three different towns. SETTINGS The towns of Raisio, Valkeakoski, and Nokia in Finland. They are equal in size and regional social deprivation indices, located in the neighbourhood of a larger city, and produce the same services to the inhabitants. SUBJECTS All permanent local government employees from Raisio (n = 887), Valkeakoski (n = 972), and Nokia (n = 934) on the employer's registers during 1991 to 1993. MAIN OUTCOME MEASURES Rates of short (1-3 days) and long (> 3 days) spells of sickness absence, irrespective of cause, and separately for infection, musculoskeletal disorder, and trauma. RESULTS In blue collar male and female workers, compared with the same sex higher grade white collar workers, the age adjusted numbers of long sick leaves were 4.9 (95% CI 4.2, 5.8) and 2.8 (2.6, 3.1) times higher, respectively. The risk varied significantly between the towns, in men in relation to long sick leaves irrespective of cause and resulting from musculoskeletal disorders, and in women in relation to long leaves resulting from infection. The numbers of long sick leaves were 3.9 (95% CI 2.8, 5.4) times higher in blue collar male workers than in higher grade white collar male workers in Raisio, 4.9 (95% CI 3.8, 6.3) times higher in Valkeakoski, and 5.8 (95% CI 4.5, 7.5) times higher in Nokia. Sickness absence of blue collar employees differed most between the towns. The rates of long sick leaves in blue collar men were 1.46 times greater (95% CI 1.25, 1.72) in Valkeakoski and 1.85 times greater (95% CI 1.58, 2.16) in Nokia than in Raisio. In men, no significant differences were found between the towns as regards the numbers of long sick leaves of higher grade white collar male workers. The socioeconomic gradients differed more between the towns in men who had worked for four years or more in the same employment than in men who had worked for shorter periods. No consistent health gradients of socioeconomic status were evident for short sick leaves among either sex. CONCLUSIONS In men and to a lesser extent in women, the workplace is significantly associated with health inequalities as reflected by medically certified sickness absence and the corresponding socioeconomic gradients of health.