Evaluating Occupation and Industry Separately to Assess Exposures in Case-Control Studies

Abstract In most occupational case-control studies, assessment of exposures is based on occupation and industry due to the lack of any other exposure information. The traditional approach to assessing exposures to specific substances is to estimate exposure for each occupation/industry combination. A modified procedure that substantially reduces the effort necessary to complete such assessments is described. In this procedure, exposure levels (none, low, medium, and high) are estimated for each occupation and industry separately. Numeric weights are assigned to these exposures levels. Final estimates for each occupation/industry combination are derived using exposure weights for occupations and industries. This method was applied to a case-control data set to estimate levels of silica exposure for the work histories of subject. The traditional method required 13,445 individual evaluations while the new approach required only 2,000 estimates. Results from the new approach were compared with those from the ...