Introduction to network meta-analysis for evidence synthesis.

Area of Science:

• Biostatistics
• Clinical Epidemiology
• Health Research Methodology

Background:

• Clinical questions often involve comparing multiple therapeutic alternatives.
• Choosing the optimal treatment requires ranking interventions by effectiveness and safety.
• Systematic reviews are crucial for synthesizing evidence on treatment comparisons.

Purpose of the Study:

• To present fundamental concepts of systematic reviews for multiple treatment comparisons using network meta-analysis.
• To explain how network meta-analysis ranks treatment effectiveness and safety.
• To introduce the modified Grading of Recommendation, Assessment, Development, and Evaluation (GRADE) approach for network meta-analysis.

Main Methods:

• Network meta-analysis simultaneously analyzes direct and indirect treatment comparisons.
• Network geometry visually represents the network structure and assesses comparison strength.
• The transitivity assumption is a key validity check, ensuring no systematic differences beyond interventions.

Main Results:

• Network meta-analysis enables the relative effectiveness assessment of all intervention pairs within a network.
• It provides a ranking of interventions based on their comparative efficacy and safety.
• A modified GRADE approach can assess evidence certainty and intervention ranking.

Conclusions:

• Network meta-analysis is a powerful tool for comparing multiple treatments in systematic reviews.
• It facilitates evidence-based decision-making by ranking interventions.
• The modified GRADE approach enhances the evaluation of evidence quality in network meta-analyses.