Conclusions about the efficiency of studies or the utility of a theory cannot be based on the outcomes of an individual research, because outcomes typically differ from one research to the next. A tool is required to integrate results across investigations.
Narrative reviews have been utilized for this objective, but such studies by different specialists can come to different decisions, and this task becomes impossibly complicated when more than a few studies are included. Meta-analysis merges the outcomes of multiple studies by applying statistical analysis to data, and it can be worked with smaller numbers of studies. Statistics have many applications in medical sciences, such as in meta-analyses... (Read more...)