Case-by-case assessment of adult-onset asthma attributable to occupational exposures among members of a health maintenance organization.

Abstract

In a general population of employed persons with health insurance, what proportion of adult-onset asthma is caused by occupational exposures? We conducted a 2-year prospective study to identify adult-onset asthma among health maintenance organization (HMO) members. Telephone interviews regarding occupational exposures, symptoms, medication use, and triggers were used to assess likelihood of work-related asthma for each case. Weighted estimating equations were used to adjust the proportion of asthma attributable to workplace exposures for factors associated with interview participation. Overall, 29% (95% confidence interval, 25-34%) of adult-onset asthma was attributable to workplace exposures; 26% (21-30%) and 22% (18-27%) of cases had asthma attributable to occupational irritant and sensitizer exposures, respectively. Occupational exposures, including irritants, are important causes of adult-onset asthma.