Why is it important to match case subjects and control subjects so closely in a case-control study?

In every experiment, control plays an important role. In a case-control study, the control subject does not change while the case subjects might differ in characteristics from each other. A case-control study is used to identify the factors contributing to a medical condition. A case subject refers to people actually suffering from the disease. A control subject refers to people who are suffering from the disease but similar to the case study.

It is very important to match case subjects and control subject to compare and contrast the results obtained from the experiment and to derive a conclusion. The control subject also keeps a track of the experiment.