ABSTRACT
Meta-analysis provides a systematic overview by drawing together quantitative primary research that has examined a particular question. Ideally using data on individuals included in each study, meta-analysis statistically combines numerical results of comparable studies or trials. By increasing the numbers of observations and the statistical power, meta-analysis aims to improve the estimates of the size of an effect or intervention or the strength of an association. The formal process of combining results from all relevant studies looking at the same health question to arrive at a final conclusion is essential for the practice of evidence-based medicine: ‘the conscientious, explicit, and judicious use of current best evidence in making decisions about the care of individual patients’1.
