Fig. 1

The discrimination and calibration curves of final risk model. a ROC curve analysis for predicting symptomatic KOA when using age, sex, waist circumference, residential area, ADL/IADL difficulty, history of hip fracture, depressive symptoms, number of chronic comorbidities, health status, and level of MPA. The AUC was 0.719 (95% CI 0.700–0.737), and optimism-corrected AUC was 0.712 after bootstrap validation. b The calibration curve. Area under the receiver characteristic curve, AUC; receiver operating characteristic curve, ROC