Fig. 8

Bias assessment “traffic light” plots of ROBINS—I protocol. This figure presents a traffic light plot used to assess the risk of bias in the included studies according to the ROBINS-I protocol. Each domain of bias assessment (such as confounding, selection bias, and missing data) is represented as a color-coded square: green indicates low risk of bias, yellow indicates moderate risk, and red indicates high risk. The plot provides a quick visual overview of the bias risks across different studies, helping to evaluate the quality of the evidence included in this review