Define systematic review and meta-analysis and explain their difference.

Define systematic review and meta-analysis and explain their difference.

• A. A narrative summary of literature.
• B. A random sampling of related studies.
• C. A qualitative synthesis of themes.
• D. Systematic review synthesizes all relevant studies on a question; meta-analysis quantitatively combines effect sizes across studies.

Answer: (D)

Systematic review and meta-analysis are two steps in evidence synthesis that work together but have different goals. A systematic review uses a transparent, pre-specified method to search for all studies addressing a defined question, apply clear inclusion criteria, assess study quality, and summarize the findings. The meta-analysis is the statistical part that may be included in a systematic review, where data from the included studies are quantitatively combined to produce a single estimate of an effect size with its uncertainty. The key difference is that a systematic review aims to comprehensively identify and evaluate all relevant evidence, while a meta-analysis provides a numerical synthesis by pooling results when the data are suitable and sufficiently comparable. If studies are too heterogeneous or data aren’t available, the review may rely on a qualitative or narrative synthesis instead of pooling. The other options describe approaches that don’t capture the full, methodical scope of systematic reviews or the quantitative pooling of meta-analysis. A describes only a narrative summary without the explicit methods, B implies random sampling of studies, and C emphasizes qualitative themes rather than quantitative synthesis.

Systematic review and meta-analysis are two steps in evidence synthesis that work together but have different goals. A systematic review uses a transparent, pre-specified method to search for all studies addressing a defined question, apply clear inclusion criteria, assess study quality, and summarize the findings. The meta-analysis is the statistical part that may be included in a systematic review, where data from the included studies are quantitatively combined to produce a single estimate of an effect size with its uncertainty. The key difference is that a systematic review aims to comprehensively identify and evaluate all relevant evidence, while a meta-analysis provides a numerical synthesis by pooling results when the data are suitable and sufficiently comparable. If studies are too heterogeneous or data aren’t available, the review may rely on a qualitative or narrative synthesis instead of pooling.

The other options describe approaches that don’t capture the full, methodical scope of systematic reviews or the quantitative pooling of meta-analysis. A describes only a narrative summary without the explicit methods, B implies random sampling of studies, and C emphasizes qualitative themes rather than quantitative synthesis.