Tips on how to write a meta-analysis by Dr. Nehad Jaser

 

Tips on how to write a meta-analysis

 

Writing a meta-analysis is a difficult endeavor that demands careful planning, strict methodology, and a clear presentation. A meta-analysis is a statistical approach that integrates the findings of several studies on a single topic or question to produce an overall assessment of the magnitude of the effect or the strength of the association between two variables. A meta-analysis can also investigate the sources of heterogeneity or variance among the studies, as well as assess the validity of various theoretical assumptions or hypotheses.

Conducting and publishing a meta-analysis involves numerous steps, and various fields may have different standards and criteria. However, the following is a general framework for producing a meta-analysis:

1. Specify the scope and research query of the meta-analysis. It is essential that the research query be precise, targeted, and pertinent to the field of study. Encompass the criteria for selecting the studies, including the population, intervention, comparison, outcome, and study design (PICOS) components, within the scope of the meta-analysis.
2. Conduct a systematic evaluation of the literature to identify the studies that are eligible. A systematic review is a thorough and transparent search of relevant databases, journals, and other information sources using predetermined keywords and criteria. Evaluators must assess the eligible studies for quality and bias risk, ensuring they meet the inclusion and exclusion criteria.
3. Extract and code data from the chosen studies. Two independent reviewers must extract and code the data, resolving any conflicts through consensus or arbitration. The data should include study information like authors, year, sample size, methodology, and results, as well as effect sizes and their variances like correlation coefficient, mean difference, standardized mean difference, risk ratio, or odds ratio.
4. Examine the data and synthesize the findings. The data should be analyzed and synthesized using appropriate statistical tools and methodologies, such as random-effects or fixed-effects models, Mantel-Haenszel methods or inverse variance, and the DerSimonian and Laird or Hartung-Knapp estimators. The overall effect size and confidence interval, heterogeneity statistics such as the I-squared, Q-test, and tau-squared, and publication bias evaluation methods such as Egger's test, the funnel plot, and the trim-and-fill method should all be included in the results.
5. Interpret and discuss the findings. The interpretation and discussion of the findings should be based on the research question and the existing literature. Researchers should compare and contrast the findings with previous studies and reviews and address the implications and limitations of the meta-analysis. The interpretation and discussion should also include the potential moderators and mediators of the effect size, such as the study characteristics, the methodological quality, and the contextual factors, as well as the possible meta-regression or subgroup analyses to explore them.
6. Prepare the report and convey the findings. The meta-analysis report and presentation should adhere to the PRISMA guidelines, which include a title, an abstract, an introduction, a methods section, a results section, a discussion section, and a conclusion section, as well as a PRISMA checklist and a flow diagram. Include tables and figures in the report and presentation that summarize the characteristics and findings of the investigations, such as the forest plot, funnel plot, and meta-regression plot.

To write a meta-analysis, you must complete these steps in order. But every phase could also include new challenges and specifics that call for additional guidance and support. For this reason, before conducting a meta-analysis, it is advisable to review pertinent literature and consult with subject-matter experts.