What is a comparative meta-analysis?
Meta-analyses can synthesize results of head-to-head comparisons of two interventions in primary studies or compare two interventions tested in different primary studies. Meta-analytic statistical procedures generate a unitless effect size for each study.
Which measure is used in meta-Analyses to compare the results across multiple studies?
One approach frequently used in meta-analysis in health care research is termed ‘inverse variance method’. The average effect size across all studies is computed as a weighted mean, whereby the weights are equal to the inverse variance of each study’s effect estimator.
Can you include independent comparisons in a meta-analysis?
It is usually reasonable to include independent comparisons in a meta-analysis as if they were from different studies, although there are subtle complications with regard to random-effects analyses (see Section 16.5.5 ).
Can a study have multiple intervention groups in a meta-analysis?
There are several possible approaches to including a study with multiple intervention groups in a particular meta-analysis. One approach that must be avoided is simply to enter several comparisons into the meta-analysis when these have one or more intervention groups in common.
How is a meta-analysis similar to a normal regression?
A meta-regression analysis is similar to a normal regression analysis, except that the heterogeneity between studies is modeled. This process involves performing a regression analysis of the pooled estimate for covariance at the study level, and so it is usually not considered when the number of studies is less than 10.
What is the difference between a meta-analysis and a systematic review?
A systematic review attempts to gather all available empirical research by using clearly defined, systematic methods to obtain answers to a specific question. A meta-analysis is the statistical process of analyzing and combining results from several similar studies.