Screening without a "gold standard": The Hui-Walter paradigm revisited

The authors consider screening populations with two screening tests but whe re a definitive "gold standard" is not readily available. They discuss a re cent article in which a Bayesian approach to this problem is developed base d on data that are sampled from a single population. It was subsequently po inted out that such inferences will not necessarily be accurate in the sens e that standard errors for parameters may not decrease as n increases. This problem will generally occur when the data are insufficient to estimate al l of the parameters as is the case when screening a single population with two tests. If both tests are applied to units sampled from two populations, however, this particular difficulty disappears. In this article the author s further examine this issue and develop an approach based on sampling two populations that yields increasingly accurate inferences as the sample size increases.