Aims: This study examined the associations of key dimensions of socioeconomic status and long sickness absence spells as well as their changes over time from 1990 to 1999.
Methods: Municipal employees of the City of Helsinki, Finland, aged 25-59 were studied. The number of participants varied yearly from 24,029 women and 6,523 men to 27,861 women and 7,521 men. Socioeconomic status was assessed by education, occupational class, and individual income. The outcome was the number of over three days' sickness absence spells/100 person years, for which the employer requires medical certification.
Results: Low education, occupational class, and individual income were consistently associated with a 2-3 times higher sickness absence rates among both men and women. The age-adjusted sickness absence rates were relatively stable from 1990 to 1994 but increased from 1994 to 1999 among men and women. Socioeconomic differences in sickness absence rates tended to increase.
Conclusions: The increase in the level of socioeconomic differences in sickness absence took place during a period of declining unemployment and staff increases at the City of Helsinki, which indicates that labour market conditions play a role in sickness absence.