BACKGROUND: The work environment has a significant impact on the burden, progression and severity of chronic disease, making employment information a valuable addition to public health surveys. The 2013–2015 Wisconsin Asthma Call-Back Survey (ACBS) indicated that more than half of currently employed adults with asthma may have work-related asthma (WRA). The burden of asthma among Wisconsin workers in specific industries and occupations has not been adequately described using multiple years of Behavioral Risk Factor Surveillance System (BRFSS) or ACBS data. In this analysis, we sought to 1) estimate asthma prevalence among employed populations; 2) compare high-risk occupations for current asthma from the BRFSS to those identified using WRA estimates from the ACBS; and 3) examine the association of current asthma with employment by occupation and other factors.
METHODS: Coded occupation responses (2002 Census Occupation Codes) from 2013–2015 BRFSS were categorized into 10 major occupation groups and merged with the 2013–2015 ACBS for WRA prevalence subanalysis. The employed population’s current asthma and WRA prevalence by occupation group were estimated with weighted survey analysis procedures. Multivariate analyses including both logistic and Cox regression were used to estimate the association between current asthma prevalence and occupation, adjusted for individual characteristics.
RESULTS: During 2013–2015, 10,830 Wisconsin residents who participated in the BRFSS had been employed within the last year; prevalence of current asthma was 8.3% (95% CI 7.5-9.1) and highest among Service occupations (12.1%) and Office/Administrative Support (10.7%), particularly among the Service subcategories Building/Grounds Maintenance workers (15.8%) and Healthcare Support occupations (16.2%). The ACBS indicated that 51.8% of currently employed adults with asthma had disease that was caused or made worse by work. Analysis by occupation confirmed high prevalence among the Service subcategories above; however, highest WRA prevalence was identified among Construction/Extraction (99.8%) and Transportation/Material Moving (84.9%). In multivariate analyses, elevated adjusted prevalence ratios (PR) for current asthma were associated with Service (PR 2.5, 95% CI 1.3-4.7) and Office and Administrative Support (PR 2.3, 95% CI 1.2-4.3) occupations, after adjustment for younger age, female gender, lower household income and obesity (all P<0.05).
CONCLUSIONS: Employment questions on the Wisconsin BRFSS can identify specific occupations with high asthma prevalence and help target workplace prevention and wellness programs. Certain Service occupations consistently reported higher prevalence of both current asthma and WRA. Aggregating additional years of ACBS data from multiple states will allow more robust estimates of the proportion of asthma attributable to work.