Meta-Analysis
A process that analyzes data from different studies done about the same subject. The results of a meta-analysis are usually stronger than the results of any study by itself.
More to read: Testing Treatments, Systematic Review
Click to enlargeA forest plot from a meta-analysis of 11 studies: a line shows the result of each study, ending with a diamond showing the results combined U.S. Agency for Healthcare Research and Quality (AHRQ)
About Meta-Analysis
In rather the same way that the play of chance can be reduced by combining data from many centres in a multinational trial, the results from similar but separate studies can sometimes be combined statistically — a process known as ‘meta-analysis’.
Although methods for meta-analysis were developed by statisticians over many years, it was not until the 1970s that they began to be applied more extensively, initially by social scientists in the USA and then by medical researchers. By the end of the 20th century, meta-analysis had become widely accepted as an important element of fair tests of treatments. Testing Treatments: Better Research for Better Healthcare