How to differentiate case control study from other study designs

The following simple criteria and flow diagrams can help us to demystify some of the confusing around case control study It contains two distinct study groups Usually conducted after the proposed outcome had already occurred Study groups are based on the outcome (with and and without outcome) Looks to compare the cause (Usually happened in the past or continues to operate front he past till present among the study groups with and without outcome

It contains two study groups Both cases and effect are already present Study groups may be based on either cause/ effect Comparison done without any explicit consideration of what is cause/what is effect

It contains two distinct study groups Usually conducted before the proposed outcome had occurred Study groups are based on the cause (with and and without cause) Investigator waits for the effect to occur and looks to compare the outcome

It contains two distinct study groups Usually conducted after the proposed outcome had occurred Study groups are based on the cause (with and and without cause) Investigator starts the study in the past and follows the groups with and without cause till the present (outcome) through the existing records..