Occupational asthma incidence: findings from the behavioral risk factor surveillance system asthma call-back survey--United States, 2006-2009.

BACKGROUND: Occupational asthma (OA) is new-onset asthma or the recurrence of previously quiescent asthma caused by workplace exposures.
OBJECTIVE: To estimate the incidence of population-based new-onset OA and the proportion of incident asthma that is work-related.
METHODS: Behavioral Risk Factor Surveillance System and Asthma Call-back Survey data collected from persons aged ≥18 years during 2006-2009 in 38 states and the District of Columbia were analyzed. Incident health professional-diagnosed new-onset OA cases were persons whose asthma was diagnosed for the first time within the past 12 months whose health professional indicated their asthma was related to their work. Incident potential new-onset OA cases were persons with asthma diagnosed within the past 12 months who did not have health professional-diagnosed work-related asthma but described their asthma as caused by workplace exposures. The proportion of incident asthma that is work-related was calculated using the 2006-2008 estimate of adult asthma incidence (3800 per million).
RESULTS: The estimated annual incidence of health professional-diagnosed new-onset OA was 179 (95% CI: 113-245) per million population. For combined health professional-diagnosed and potential new-onset OA the incidence was 692 (95% CI: 532-853) per million population. The proportion of incident asthma among adults that is work-related was 4.7% for health professional-diagnosed new-onset OA and 18.2% for combined health professional-diagnosed and potential new-onset OA.
CONCLUSIONS: New-onset asthma in as many as one of six adult patients might be associated with work. Clinicians should consider the role of occupational exposures when evaluating adults with incident asthma which may uncover opportunities for early intervention and reversal of an otherwise chronic disease.