What is meta-analysis?


Meta-analysis is a systematic and quantitative method (a.l.*) for combining the results of previous studies to get appropriate evidence-based conclusions. The combination of results could be in the form of pooled statistical results / overall effect size.

This may include the following processes:

1. Formulating a research question.

2. Searching the required articles and relevant information. It may also include working on on inclusion and exclusion criteria utilizing “Preferred Reporting Items for Systematic Reviews and Meta- Analyses (PRISMA)” to note the flow of information.

3. Collection of abstract data, such as Sample size, age of participants, outcomes, etc.

4. Statistical analysis, including

A. Calculation of effect size, including the development of forest plot. Here, effect size is the size of the difference of effect between two groups.

B. Heterogeneity statistics, including Q statistics, Tau-squared, I-squared, and including plots, such as Funnel plot, Baujat plot, L’Abbe plot. Here, Q statistics is the ratio of observed variation to within-study variance.

Zusammenfassung in deutscher Sprache (Summary in German language)

Die Metaanalyse ist eine quantitative Methode, um die Ergebnisse früherer Studien zu kombinieren. Es umfasst die Berechnung von Effektgrößen- und Heterogenitätsstatistiken, z. B. Q-Statistiken und Trichterdiagramme.


Paracha, U. Z. (2019). Colorful Statistics with Basic Steps in Minitab(R) 19. Independently Published. https://books.google.com.pk/books?id=9_6kyAEACAAJ

*a.l.=affiliate link

Usman Zafar Paracha

Usman Zafar Paracha is a sort of entrepreneur. He is the author of "Color Atlas of Statistics", and the owner of an Android game "Faily Rocket."