Interpretation of data from multiple trials: a critical review

Area of Science:

• Medical Research Methodology
• Biostatistics
• Evidence Synthesis

Background:

• Meta-analysis, a statistical technique for combining results from similar investigations, was first described in 1976.
• The practice has evolved significantly, with thousands of meta-analyses published to date.
• Meta-analyses can be conducted narratively or, more rigorously, using statistical methods.

Purpose of the Study:

• To review the current status and methodology of meta-analysis.
• To present and discuss criteria for designing and executing high-quality meta-analyses.
• To highlight potential pitfalls and the importance of attention to detail in meta-analysis.

Main Methods:

• Review of the evolution and current practices of meta-analysis.
• Detailed discussion of quality criteria, including study selection, bias assessment, and heterogeneity analysis.
• Presentation of critical reviews and examples from hepatology research.

Main Results:

• Meta-analysis has evolved into a complex but powerful tool for evidence synthesis.
• High-quality meta-analysis demands rigorous attention to detail in study selection, quality assessment, and heterogeneity management.
• Improper execution can lead to ambiguous or erroneous conclusions.

Conclusions:

• While conceptually simple, meta-analysis is complex to perform correctly.
• Adherence to stringent methodological criteria is essential for generating reliable and valid results.
• Expertise and careful execution are crucial to harness the full potential of meta-analysis in scientific research.