Case control studies are of a great importance in estimating causal and noncausal associations between variables in medical research. They are distinguished by the exchangeability property of odds Ratio which let us predict the future using past experience. Case control design needs less subjects and impose less ethical challenges in comparison to Cohort design. Besides this design has the potential to be even more efficient by methodological tricks. One outstanding features of case control design is that it can be combined with cohort design to make it less vulnerable regarding its potential drawback which is selection of controls. This blessed combination could provide the researchers to estimate risk ratio or rate ratio even when the rarity assumption is not met. However, researchers are less familiar with the advantages of case control design and as a result this design is rarely used specially by clinical researchers. So the aim of this course is to make young researchers more familiars with the potentials of case control design.

• Why case control studies?
• General structure of Case-Control Studies
• Measures of frequency and measures of association
• Common biases and fallacies in Case-Control Studies
• Matching in Case-Control Studies
• Sample size for Case-Control Studies
• Analysis of Case-Control data
• Variants of Case-Control Studies including nested case control and case cohort studies and …