The association between occupation and asthma in general medical practice

In general practice settings, the proportion of adult asthma attributable to occupational factors is not known.

The goal of this study was to estimate the proportion of adult asthma cases that can be attributed to occupational factors initiating new disease onset and exacerbating preexisting disease.

We performed a cross-sectional analysis of interview data for 150 adults with asthma recruited from a random sample of family practice specialists. We ascertained the asthma and work histories of the subjects and estimated the proportion with likely work-initiated asthma and work-related asthma recrudescence.

Seventy-four subjects (49%) reported adult-onset asthma while employed; an additional 25 (17%) reported recrudescence of previously quiescent childhood-onset asthma during employment. Of those with new-onset asthma while employed, 15 (10% of the study group; 95% confidence interval, 5 to 15%) were employed in occupations at increased risk of occupational asthma initiation on the basis of an independent job scoring matrix. Of those with asthma recrudescence in adulthood, seven (5% of the study group; 95% confidence interval, 2 to 8%) were employed in occupations at increased risk of exposures aggravating asthma.

Among adults with asthma treated in general practice settings, > 1 in 10 patients has a work history strongly suggestive of a potential relationship between exposure and disease.