Self reported rate of occupational asthma in Sweden 1990-2

Abstract

Objectives: To estimate the annual rates of self reported occupational asthma in different occupational groups in Sweden.

Methods: All claims of occupational asthma 1990-2 in the Swedish register of reported occupational diseases were classified according to occupation. The number of people employed in each occupational group in the general population was obtained from the 1990 national census. Reporting rates (cases/million/ year) were calculated for each occupation with more than five reported cases, according to sex and age (20 to 64 years, and 20 to 44 years).

Results: 1010 cases were reported giving an annual crude reporting rate of 80/million (95% confidence interval (95% CI) 70 to 90). For men, the crude reporting rate was 91/million (95% CI 84 to 98), and for women 70/million (95% CI 80 to 106). The highest reporting rates were among male bakers-(775/million), furnacemen (702/million), male welders (647/million), female chemical and plastic production workers (629/million), and female poultry and dairy farm workers (602/million).

Conclusions: A surveillance system based on self reporting is influenced by considerable bias, especially reporting bias. However, results for the specific occupations with high rates were similar to those found with other surveillance systems. This indicates that our system is a useful one.