Was a consecutive or random sample of patients enrolled?  This will be similar for all index tests, target conditions, and populations.YES: if a study explicitly stated that all participants within a certain time frame were included; that this was done consecutively; or that a random selection was done.NO: if it was clear that a different selection procedure was employed; for example, selection based on clinician's preference, or based on institutions.UNCLEAR: if the selection procedure was not clear or not reported.