Screening of controls in cass-control study of infectious diseases

Ｓｃｒｅｅｎｉｎｇｏｆｃｏｎｔｒｏｌｓｉｎｃａｓｓ－ｃｏｎｔｒｏｌｓｔｕｄｙｏｆｉｎｆｅｃｔｉｏｕｓｄｉｓｅａｓｅｓＬｉＬｉａｎｇｓｈｏｕ（李良寿）；ＸｕＤｅｚｈｏｎｇ（徐德忠）；ＹａｎＹｏｎｇｐｉｎｇ（阎永平）（ＤｅｐａｒｔｍｅｎｔｏｆＥｐｉｄｅｍ...

Screening of controls in cass-control study of infectious diseases

A simulation analysis and a comparative study of hepatitis were undertaken between susceptible population control (SPC) and general population control (GPC). It was shown that when the exposure rate for studying factors in susceptibles was approximate to that of general population. the values of Odds ratios (ORs) of the two control groups were also approximate. When there was an significant difference in exposure rates between the two control groups, the difference of values of ORs of the two control groups might be significant, but the ORs were approximate to relative risk (RR) of the corresponding target population. According to these results, the authors are of the opinion that whether serological screening is needed during the selection of control in case-control study of infectious diseases is determined by the efficacy of serological screening and the association of aims of research. If there is no significant association between exposure and susceptibility, or the estimates of ORs of general population are desirable, the GPC is preferable. When the estimates of ORs of susceptible population are wanted, the susceptible population control should be selected.