Risk Assessment Plots

Risk Assessment Plots assesses improvements in clinical risk prediction models by calculating Net Reclassification Improvement (NRI), Integrated Discrimination Improvement (IDI), and Area Under the Curve (AUC) differences and visualizing these metrics to evaluate the added value of new biomarkers.

Key Features:

• Net Reclassification Improvement (NRI): Quantifies how a new biomarker reclassifies individuals into different risk categories compared to an existing model.
• Integrated Discrimination Improvement (IDI): Measures change in discrimination between those with and without an event after incorporating a new biomarker.
• Area Under the Curve (AUC) Difference: Calculates differences in AUC to compare overall diagnostic performance before and after adding a biomarker.
• Risk Assessment Plot Visualization: Graphically represents NRI, IDI, and AUC differences to illustrate how adding a biomarker affects calculated risks across patient groups.

Scientific Applications:

• Biomarker evaluation in clinical research: Assess the impact of adding biomarkers such as urinary cystatin C on risk models predicting outcomes including acute kidney injury (AKI), sepsis, and 30-day mortality.
• Detection of subtle model changes: Identify shifts in calculated risks that may not be evident from traditional metrics alone by combining NRI, IDI, and AUC comparisons with visualization.

Methodology:

Risk prediction models compute individual event probabilities, new biomarkers are integrated into these models, NRI and IDI are calculated to quantify diagnostic improvement and AUC differences are computed, and the results are displayed using risk assessment plots.