Risk of Bias (RoB) assessment is a fundamental methodological component of Systematic Reviews and Meta-Analyses used to evaluate the scientific quality, credibility, and reliability of included studies. Its primary aim is to identify whether flaws in study design, methodology, conduct, analysis, or reporting may systematically affect the validity of the results and potentially lead to misleading conclusions. In evidence-based research, statistically significant findings alone are insufficient; the methodological integrity of the evidence must also be critically assessed before interpreting the final conclusions.

Risk of Bias assessment is important for most analytical study designs, including:

• Randomized Controlled Trials (RCTs)
• Cohort Studies
• Case-Control Studies
• Cross-Sectional Studies
• Diagnostic Accuracy Studies
• Prognostic Studies
• Non-randomized interventional studies

Because different study designs have different methodological limitations, there is no single universal Risk of Bias tool appropriate for all studies. Instead, several internationally recognized tools have been specifically developed for different research designs.

In Systematic Reviews and Meta-Analyses, the Risk of Bias methodology is usually described in the Methods section, where researchers explain:

• which assessment tool was used,
• how the assessment was performed,
• how disagreements between reviewers were resolved,
• and how the final judgments were determined.

The final Risk of Bias results are generally presented in the Results section using:

• tables,
• traffic-light plots,
• summary graphs,
• or supplementary materials.