Description: Meta-analysis is a statistical approach that combines the results of multiple scientific studies to obtain more robust and generalizable conclusions. This method allows researchers to synthesize data from different investigations, thereby increasing statistical power and the accuracy of results. Through meta-analysis, patterns, discrepancies, and trends that would not be evident when analyzing a single study can be identified. This approach is especially valuable in fields such as medicine, psychology, and social sciences, where the results of individual studies can vary significantly. By integrating data from various sources, meta-analysis provides a more comprehensive and objective view of a phenomenon, helping researchers make informed decisions based on accumulated evidence. Additionally, it allows for the evaluation of the consistency of observed effects and the exploration of potential sources of heterogeneity among studies, contributing to a better understanding of the researched topics.
History: The concept of meta-analysis began to take shape in the 1970s, although its roots can be traced back to the work of statisticians like Karl Pearson and Ronald Fisher in the 20th century. However, it was in 1976 that the term ‘meta-analysis’ was coined by American psychologist Gene V. Glass, who defined it as a method for combining results from independent studies. Since then, meta-analysis has evolved and become an essential tool in scientific research, especially in medicine, where it is used to assess the effectiveness of treatments and therapies.
Uses: Meta-analysis is primarily used in various research fields to evaluate the effectiveness of interventions and treatments, allowing researchers to summarize existing evidence and formulate recommendations based on data. It is applied in psychology to analyze the effectiveness of psychological therapies and in social sciences to study complex phenomena from multiple studies. Additionally, meta-analysis is useful in the development of guidelines and policies, as it provides a solid evidence base.
Examples: An example of meta-analysis is the study conducted by Borenstein et al. in 2009, which analyzed the effectiveness of cognitive-behavioral therapy in treating depression by combining data from multiple clinical trials. Another case is the meta-analysis of the effectiveness of flu vaccines, which has allowed researchers to assess their impact on different populations and health conditions over the years.
