Socioeconomic and occupational groups and risk of asthma in Sweden

To investigate possible associations between hospitalization for asthma and socioeconomic status and occupation.

A nationwide database was constructed by linking Swedish Census data to the Hospital Discharge Register (1987-2004). The hospital diagnoses of asthma were based on the International Classification of Diseases. Standardized incidence ratios were calculated for different socioeconomic and occupational groups. Ninety-five per cent confidence intervals were calculated assuming a Poisson distribution.

A total of 13,202 male and 11,876 female hospitalizations for asthma were retrieved at ages >30 years. The socioeconomic groups with < 9 years of education were associated with a significantly increased risk of hospitalization for asthma. Among male occupations, increased risks were noted for farmers, mechanics and iron and metal workers, welders, bricklayers, workers in food manufacture, packers, loaders and warehouse workers, waiters and chimney sweeps with prolonged exposures in two censuses. For female occupations, increased risks were observed among assistant nurses, religious, juridical and other social science-related workers, drivers, mechanics and iron and metalware workers and wood workers.

The present study suggests that socioeconomic status (low educational level) and occupation have an effect on the population's risk of hospitalization for asthma.