BACKGROUND:

Disability among those with asthma is common and costly. Little is known about the causes of disability in asthma; experience with other chronic diseases suggests that illness severity alone does not adequately predict disability. There is a theoretical and experimental basis upon which to postulate that other variables, including factors such as job flexibility, asthma self-efficacy, social supports, and cigarette smoking may be predictors of disability in asthma. The study helped to explain the inter-relationships among illness severity, other co-factors and disability in asthma, addressing a major research gap.

DESIGN NARRATIVE:

The study was a cross-sectional survey, including retrospective work history data. A random sample was conducted of 40 board certified pulmonologists in Northern California enrolling persons with asthma. Pulmonologists maintained a log of all persons meeting a clinical definition of asthma presenting to their offices for treatment over a one month period. A total of 601 subjects with any history of laborforce participation were interviewed by a trained survey worker in order to assess severity of disease using a severity scale based on symptoms, medications, and past-asthma history. The computer-assisted, telephone-administered interviews used established survey instruments to assess psychosocial variables, smoking exposure and work history.