Meta-analysis is a method that allows us to accomplish such a work by combining the results of several studies in order to make an objective synthesis following precise stages. With the help of meta-analysis, we can quantify a global result for the entire studies taken into consideration and obtain a more precise response and a more acceptable generalization.

This paper focuses on the steps of meta-analysis on resumed data, which are used more frequently, because they can easily tend towards exhaustiveness. The synthesis work has to be standardized. It consists in four stages: studies’ research, selection, data extraction and analysis. Its feasibility is linked to the existence of a sufficient number of studies that can be included in this meta-analysis. This method has been used in research since 1970 and it became irreplaceable for making recommendations. Its application field is only limited to that of existent studies.