Assessment of occupational exposures in community-based case-control studies.

Assessing occupational exposures in community-based studies is a challenge for investigators because there are no standardized or validated approaches for collecting information regarding occupational history. The strengths and limitations of the methods available for assessing occupational exposures are reviewed. In community-based case-control studies, the prevalence of most chemical agents is low. The common sources of misclassification in these studies are addressed, as are strategies for dealing with misclassification bias. Methods to assess the presence and magnitude of differential reporting by cases and controls are outlined, together with analytic strategies to improve the classification of occupational exposures.