Nested case–control study: Difference between revisions

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Case-cohort study: Someone had incorrectly written that the control group for a case-cohort study is a random sample of the *non-cases,* but in fact the control group could include cases.
Description introduction clarified and simplified.
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A '''nested case control (NCC) study''' is a variation of a [[case-control study]] in which only a subset of controls from the cohort are compared to the incident cases. In aeach case-control study,is all incident cases in the cohort are comparedmatched to aone randomor subsetmore ofcontrols participantsbased whoon doparticipant notcharacteristics, develope.g. the disease of interestage. In contrast, in a nested-standard case-control study, somea numberset of controls are selected for each case from that case's matched risk set. Bywithout matching on factors such as age and selecting controls from relevant risk sets, the nested case control model is generally more efficient than a case-cohort design with the same number of selected controls.
 
Usually, the exposure of interest is only measured among the cases and the selected controls. Thus the nested case control study is less efficient than the full cohort design. The nested case control study can be analyzed using methods for missing covariates.<ref name=Cai/>