Healthy People 2030

KAISEN: A reproducible five-phase fairness audit pipeline for clinical risk models, stress-tested to failure

KAISEN is a five-phase audit pipeline for subgroup fairness in clinical risk models, covering stratification, disparity measurement, mechanism diagnostics, post-hoc mitigation, and drift monitoring. The authors evaluate it on a synthetic benchmark of 16 disease tasks and 15 social-determinant axes, deliberately stress-testing each component to identify failure modes. Key findings include that per-group threshold optimization reliably reduces equalized-odds disparity while group-wise Platt scaling behaves near-randomly on that metric, and that the mechanism diagnostic fails silently under proxy misspecification. All code and artifacts are released for full reproducibility.