Standardization in the retrospective evaluation by experts of occupational exposure to organic solvents in a population-based case-control study.

Epidemiologists carrying out retrospective evaluation of occupational exposure to solvents often use experts to assist in drawing up and interpreting structured questionnaires. However the epidemiologist cannot pass complete responsibility to the expert for deciding on the relative importance of the different exposure variables. Expert assessment of exposure to organic solvents was carried out in a population-based case-control study. The process of expert evaluation was examined and the different steps in the process identified. This paper describes work in progress on the formalization of the rules that experts use to identify and quantify exposure.