Do systematic reviews always include a meta-analysis?

Systematic reviews are comprehensive evaluations of existing studies on a particular topic, synthesizing evidence to make conclusions regarding that topic. While a meta-analysis is a statistical method that pools results from different studies to provide a more precise estimate of effect, it is not a mandatory component of every systematic review.

The primary aim of a systematic review is to answer specific research questions based on the best available evidence, and if the studies included are too heterogeneous in terms of their study design, interventions, populations, or outcomes, a meta-analysis may not be feasible or appropriate. This means that a systematic review can be conducted without performing a meta-analysis, presenting the findings qualitatively instead. Such reviews provide valuable insights, even without the pooling of data.

In contrast, while systematic reviews often focus on summarizing data through meta-analysis when applicable, it is essential to understand that they can also deliver a comprehensive review of available evidence without conducting a meta-analysis due to various reasons, such as variability among included studies or other limitations. Therefore, the assertion that systematic reviews can exist without a meta-analysis is accurate.