Asthmatic subjects symptomatically worse at work - Prevalence and characterization among a general asthma clinic population

Study objectives: To assess the prevalence of a historical occupational com ponent to asthma in an adult asthma clinic and to compare characteristics o f asthmatic subjects with and without work-attributed symptoms. Design: A retrospective review of data obtained from a physician-administer ed questionnaire, answers to which were obtained at the initial patient vis it of asthmatic subjects, and which included specific questions regarding t he relationship of work to symptoms. Chart review data were used to supplem ent information on workplace exposures and investigations. Setting: A university-based secondary- and tertiary-referral asthma clinic. Patients: Seven hundred thirty-one adult asthmatic subjects who were referr ed for assessment and management of asthma. Interventions: Statistical analyses of asthmatic subjects with and without work-attributed symptoms and a determination, from chart review, of the lik elihood of causes for symptomatic worsening of asthma at work. Measurements and results: Sixty percent of the patients (435) had adult ons et of asthma, among whom 310 patients (71%) were employed at the time of th eir visit. Fifty-one patients reported their asthma to be worse at work (ie , 16% of adult-onset working asthmatic subjects). Sixteen of these patients (31%) had likely or possible sensitizer-induced occupational asthma (OA), and 49% likely had aggravation of underlying asthma. The other 20% of patie nts had possible OA or aggravation of underlying asthma at work. Conclusions: Adult-onset asthmatic subjects commonly report a worsening of asthma at work, more commonly on the basis of likely aggravation of underly ing asthma than on the basis of likely or possible OA.