GDF15 and Alzheimer disease: The area under the curve (AUC, Harrell's C‐statistic) to predict AD/RCA increased from 0.68 (95% CI: 0.55‐0.81) for age, sex and LVEF to 0.76 (95% CI: 0.64‐0.88; P = .034; Table 3) when GDF‐15 was added to a model.