“…That is, that they should not be cases; otherwise, what will be identified as false-positive cases will actually be true-positive cases. Two studies in particular (by Bennett et al [7] and Marcus et al [8]) showed low specificity for the 2010 criteria, based on not excluding cases from the control group. This is a problem for criteria studies, rather than a true diagnostic problem where one could, for the purpose of the study, either include, exclude, or measure separately patients with concomitant illnesses.…”