Comparison of 3 methods for assigning exposure metrics for evaluating occupation effect upon COPD.
Harber P; Simmons M; Tashkin D; Hnizdo E; Crawford L; Connett J
Proc Am Thorac Soc 2005 May; 2(Abstracts):A818
Spirometry and work descriptive data from the Lung Health Study, a multi-site early, intervention (smoking cessation/bronchodilator) clinical trial, were analyzed to assess the influence of occupational exposures upon the lung function at the baseline examination in 3025 male smokers with early COPD. Subjects were assigned to 55 workgroups using a computerized lexical analysis system for interpretation. Exposure was summarized by three methods: SR: Individual self reported response to questions about dust and fume at the worksite; GAR: Group Average Response- proportion of subjects in each workgroup reporting the exposure; and JEM: Job Exposure Matrix-ratings assigned by a panel of four experts to each workgroup. The health outcome variable was spirometry measurements at baseline pre and post bronchodilator administration. The predictor variables included occupational exposure, smoking intensity, and airway responsiveness by methacholine challenge testing. After adjustment for smoking intensity and airway responsiveness, there was statistically significant negative association between FEV1 % predicted and exposure when exposure was determined by the JEM and by JEM and GAR weighted by years in the job, but not by SR(e.g. a l point increase in fume exposure by JEM [scale 1-10] was associated with a 0.219 % predicted reduction in mean FEV1 post bronchodilator). Occupational exposures, particularly fume exposure, are associated with reduction of lung function in males with early COPD. The new method of computerized lexical analysis to assign individuals into workgroups is an effective epidemiologic tool. Exposure described on a group basis appears to be more effective than using individual self-stated exposures.
Occupational-exposure; Lung-function; Spirometry; Smoking; Demographic-characteristics; Sex-factors; Exposure-assessment; Fumes; Fumigants; Statistical-analysis; Surveillance
Abstract; Conference/Symposia Proceedings
Issue of Publication
Disease and Injury: Asthma and Chronic Obstructive Pulmonary Disease
Proceedings of the American Thoracic Society. 2005 ATS International Conference, May 20-25, 2005, San Diego, California