Fig. 2

Calibration curves for different models. A Model 1, (B) Model 2, (C) Model 3, (D) Model 4, (E) Model 5, and (F) Model 6. Note. Model 1 incorporated seven predictors, including gender, age, smoking, self-report health condition, BMI, depressive symptoms, and cognitive function. Besides, five physical performance-based models were established based on Model 1, adding handgrip strength (Model 2), SPPB (Model 3), gait speed (Model 4), handgrip strength plus SPPB (Model 5), and handgrip strength plus gait speed (Model 6), respectively. Model-predicted probability and actual probability for ADL disability among older adults were plotted in the x- and y-axis, respectively. The diagonal gray line represents an ideal plot for the calibration plot. The solid black line represents the performance of the prediction model, of which a closer match to the diagonal gray line indicates a better calibration