A systematic (or narrative) review provides a summary of prior findings on a specific topic (or a relation) in a body of research. It is mainly descriptive. While it can identify the inconsistent findings and gaps in the literature, it cannot empirically explain the reasons underlying these inconsistent findings. In contrast, a meta-analysis is an empirical methodology that uses the effect sizes (e.g., correlations) from prior studies to statistically test hypotheses about the reasons for the inconsistencies in the literature. In other words, a meta-analysis can provide a quantitative synthesis of the findings in the literature, while systematic review only provides a descriptive summary of them.
Meta-analysis requires more data and details of the primary studies (e.g., correlations between variables of interest, sample sizes), which you do not normally need for a systematic review. The availability of those data is an important condition for the feasibility of conducting a meta-analysis. Therefore, it is not always feasible to conduct a meta-analysis. However, the requirements for conducting a systematic review are less restrictive. Therefore, they are more common.
There are different methodologies for conducting a meta-analysis. The following seminal book by Hunter and Schmidt is a great reference to familiarize yourself with the common methods of meta-analysis:
Hunter, J.E., and Schmidt, F.L. 2004. Methods of Meta-Analysis: Correcting Error and Bias in Research Findings, (Second ed.). Sage Publications, Inc.
There are different tools available for meta-analysis, including different R packages. I recommend metafor package: http://www.metafor-project.org/doku.php. They have a listserv where you can find answers to meta-analysis questions using metafor.
We also presented a workshop on meta-analysis a few years back. You can find its PowerPoint slides with some examples and codes here: Presentation Introduction to Meta-Analysis
Some of the example data files and syntax for this workshop are accessible on my personal website: https://facsrv.cdm.depaul.edu/~hqahrisa/#service.
Even though there is some overlap, the aim of both is to collect and use previously published data. Most systematic reviews include a meta-analysis.
A meta-analysis is a combination of previously published research. It is a quantitative examination of previously published data.
A systematic review also collects previously published work, simply it takes a further qualitative look. The focus is on the magnitude of the effect, rather than on statistical significance like it is the case with meta-analysis. It includes a lot of narrative and adds a lot of detail to the topic at hand.
According to the Cochrane definition, systematic reviews aim to “identify, appraise and synthesize all the empirical evidence that meets pre-specified eligibility criteria to answer a specific research question”.
A meta-analysis is a combination of the results of individual studies aimed at producing an overall statistic.
Therefore, a systematic review may (or may not) be coupled with a meta-analysis, which is usually considered feasible when study findings are sufficiently homogeneous (in terms of PICOS criteria) and when the pooled estimate is meaningful.
In brief, it is a matter of difference between qualitative and quantitative methods to synthesize the scientific literature.
Check this article for a full explanation: Article Reading and interpreting reviews for health professionals: a...
If you are looking for a textbook about how to perform a meta-analytical work, then I recommend you this valuable source of methodological instructions:
A systematic review searches for the answer to a particular question in the existing scientific literature on a topic.
A meta-analysis compares and combines the findings of previously published studies, usually to assess the effectiveness of an intervention or mode of treatment.
Systematic literature reviews increasingly employ theory or aim to develop it further. Please find a crisp contrasting of four related approaches in this paper:
Article The application of theory in literature reviews – illustrate...