Meta-Analyses

Within a field of research a summary of different investigations can be made. Such a compilation is called meta-analysis. The individual results of identical primary studies are summarised. The aim of a meta-analysis is to investigate whether an effect is actually present and if so, how large it is. In medicine and other sciences, they help with two problems: Often - mostly for cost reasons - the samples of the primary studies are much too small to produce reliable results. If one now summarizes many single examinations suitably, then the result won with it is much more exact and safer. Often the primary studies do not use exactly the same methods, definitions or draw their samples from the same population. Here it is questionable whether and how these influences can be separated from the object of the investigation at all.