Are workers at greater risk of undiagnosed asthma?

Abstract

Background: The risk of asthmatic symptoms without a diagnosis of asthma is rarely researched, especially in relation to work and social class. Aim: To investigate whether the risk of undiagnosed asthma (i.e. individuals with asthma-specific symptoms without a physician diagnosis) differed by socioeconomic status and occupation. Methods: The study population (n=6165) was an adult random population sample from Northern Sweden answering a postal questionnaire in 2006 within the OLIN-studies. Results: The prevalence of physician diagnosis of asthma was 11.5%, asthmatic wheeze (wheeze with breathlessness without having a cold during the last 12 months) 7.4% and undiagnosed asthma (those reporting asthmatic wheeze but no physician diagnosis) 3.6%. Using the Socioeconomic Classification of Statistics Sweden, the highest proportion of undiagnosed asthma was found in manual workers in industry (3.8%, p =0.064), service, (3.8%, p=0.062) and non-manual workers (3.9%, p=0.056) compared to 1.8% among professionals and executives (p-values in comparison with the latter). In a logistic regression model adjusting for age and sex the risk of undiagnosed asthma was increased among manual workers in industry (OR 2.28, p=0.062) and service (OR 2.11, p=0.085) and among non-manual workers (OR 2.14, p=0.077) with professionals and executives as reference. With the Standard of Swedish Classification of Occupations; 2.5-5.5% of individuals in service- and goods-producing occupations had an undiagnosed asthma, compared to 3-4% among those in occupations requiring a higher level of education and 3% among executives. Conclusion: The results indicate that workers may have a higher risk of undiagnosed asthma when compared to professionals and executives.