  In epidemiological studies, very often, evaluators obtain measurements of
disease outcomes for study participants. In this paper, we propose a two-stage
procedure for detecting outlier evaluators. In the first stage, a regression
model is fitted to obtain the evaluators' effects. The outlier evaluators are
considered as those with different effects compared with the normal evaluators.
In the second stage, stepwise hypothesis testings are performed to detect
outlier evaluators. The true positive rate and true negative rate of the
proposed procedure are assessed in a simulation study. We apply the proposed
method to detect potential outlier audiologists among the audiologists who
measured hearing threshold levels of the participants in the Audiology
Assessment Arm of the Conservation of Hearing Study, which is an
epidemiological study for examining risk factors of hearing loss.
