Predictive Models Aid Prognostication Secondary Analysis Integrating Model and Physician Prognostic Estimates in Heart Failure

BACKGROUND: In a recent multicenter Canadian study in heart failure (HF), model predictions proved more accurate than physicians. OBJECTIVES: Simulating clinical practice, the authors evaluated the predictive value of combining model predictions with physician estimated 1-year mortality in HF outpatients. METHODS: This post hoc analysis of a Canadian multicenter cohort study included HF outpatients (left ventricular ejection fraction ≤40%). HF cardiologists and family doctors estimated patient 1-year mortality using clinical judgment. The Seattle HF Model (SHFM) predicted mortality. All patients were followed for 1 year to collect mortality. Stratified by specialty, we compared the performance of SHFM and physician estimates alone, with a model integrating physician and SHFM predictions using a random forest survival model, evaluating discrimination (C-statistic), calibration (observed vs predicted event rate), risk reclassification, and clinical net benefit. RESULTS: In 1,643 HF patients, 1-year mortality was 9% (95% CI: 8%-11%). The SHFM had adequate discrimination (C-statistic 0.76; 95% CI: 0.72-0.80) and excellent calibration. Physicians showed adequate discrimination (0.75; 95% CI: 0.71-0.79 for cardiologists; 0.72; 95% CI: 0.66-0.78 for family doctors) and poor calibration with significant risk overestimation. Integrating SHFM and physician predictions, discrimination significantly improved (0.82; 95% CI: 0.78-0.86 for cardiologists; 0.87; 95% CI: 0.83-0.91 for family doctors) with excellent calibration. By risk reclassification, among patients without events, the integrated model better risk-classified 71% (95% CI: 70%-72%) vs cardiologists and 60% (95% CI: 58%-61%) vs family doctors; among patients with events, the model misclassified 45% (95% CI: 58%-63%) vs cardiologists and 11% (95% CI: 25% to 3%) vs family doctors. The integrated model led to higher clinical benefit. CONCLUSIONS: Integrating SHFM predictions with physician judgment improved accuracy. Model-informed assessment provides prognostic accuracy for clinical decision-making. (Predicted Prognosis in Heart Failure Intuition; NCT04009798).