Assessing exposure misclassification by expert assessment in multicenter occupational studies.

Background: In a multicenter case-control study of lung cancer in central and eastern Europe and in Liverpool, exposure to occupational agents was assessed by teams of local experts. We performed an interteam agreement study to estimate the levels of exposure misclassification and the expected attenuation of the risk estimate.

Methods: Eight teams of experts and a reference rater assessed exposure to 70 putative lung carcinogens for 19 jobs.