 The second, standard matched case-control studies (CC) demands that one person who accompanies the symptomatic persons to the test facility is asked the same information .
<clarity>  The second, standard matched case-control studies (CC) demands that one person who accompanies the symptomatic persons to the test facility is asked the same information .
 The second, standard matched case-control studies (CC) with population controls, requires the collection of data on one or more population controls for each person who is tested in the test facilities, so that test-positives and test-negatives can each be compared with population controls .