CONSEQUENCES ON THE VALIDITY OF META-ANALYSES

Familiarity with the methodological framework of meta-analysis is essential to assess its validity in achieving research objectives.

What are the potential consequences of publication bias on the validity of meta-analyses? Publication bias can significantly impact the validity of meta-analyses in several ways:

• Influence on Meta-Analytic Results: Publication bias can suppress unfavourable studies, biasing meta-analytic results towards an artificially favourable direction.
• Detection Challenges: Various statistical tests have been proposed to detect publication bias. However, they often make different assumptions and may have low power in many cases, making it challenging to select the optimal test for real-world meta-analyses.
• Low Rates of Assessment: A review of meta-analyses in plastic surgery and psychology journals revealed low rates of proper publication bias assessment, with only a small percentage attempting to correct for its effect.
• Impact on Conclusions: Studies have shown that publication bias can lead to overestimated effects and false-positive results, affecting the validity of meta-analytic conclusions.
• Detection Method Limitations: P value–driven tests for publication bias may underestimate its presence, mainly when the number of studies in the meta-analysis is small.

In conclusion, publication bias can have significant consequences on the validity of meta-analyses, including biasing results, impacting conclusions, and posing challenges for detection. The low rates of proper assessment and the limitations of detection methods further emphasize the need for careful consideration of publication bias in meta-analytic research.