From Grant (2009): A meta-analysis is a technique that statistically combines the results of quantitative studies to provide a more precise effect of the results. Put another way, it is a statistical technique for combining the results from different studies on the same topic. (Lee, 2018). When done correctly, a meta-analysis can explore the sources of heterogeneity, and identify subgroup, ultimately and --hopefully-- providing new insights for future studies. Meta-analyses are considered to be. specialized subsets of systematic reviews.
Not all systematic reviews will include a meta-analysis but all meta-analyses are found in systematic reviews.
What is the difference between a systematic review and a meta-analysis?
In short, the following best summarizes the core differences between these two study designs...
- A systematic review refers to the entire process of selecting, evaluating, and synthesizing all available evidence.
- A meta-analysis refers to the statistical approach to combining the data that is derived from a systematic review.
Before conducting a meta-analysis, researchers should ask themselves the following question:
Are there enough primary studies for a meta-analysis?
Although a meta-analysis can be conducted with just a small pool of studies, it is worth considering what this lack of available literature implies. It could suggest that the topic/subject may not be mature enough to yield useful findings (Cheung, M., & Vijayakumar, R., 2016).
