Exposure Assessment Using Occupation- and Industry-Specific Modules
Occupation- and industry-specific modules ask detailed questions about work activities and exposures within its population-based case-control studies to better capture within-occupation differences in exposure. Usually these module responses are reviewed job-by-job by an exposure assessor to assign exposure estimates. DCEG investigators in the Occupational and Environmental Epidemiology Branch (OEEB) develop methods to more efficiently and transparently assign exposure in studies that use modules and examine the validity and reliability of these methods. Decision rules that link questionnaire responses to exposure estimates have been developed to assess occupational exposures in U.S. case-control studies, including metalworking fluids, diesel exhaust, lead and benzene.
In an evaluation of the reliability of decision rule approaches, investigators found that decision rule estimates of occupational diesel exhaust exposure for the New England Bladder Cancer Study had moderately-high agreement with estimates obtained from expert reviews of each job. Exposure estimates in the decision rules are data-driven wherever possible, including use of subjects’ answers to occupation and industry-specific modules and use of job group medians derived from module responses to assign exposure to those in similar jobs without a completed module. Intensity estimates are based on synthesis of publicly available data sources whenever possible (see next section). Investigators have also developed a method to extract patterns in the questionnaire responses that predict an expert’s exposure assignments using classification and regression tree (CART) models. The extracted decision rules have been used to improve the transparency and efficiency of applying the exposure decisions to other study subjects.
For more information, contact Dr. Melissa Friesen