Fig. 2

Calibration curves in the overall cohort for the models before (upper panel) and after the intercept adjustment (lower panel). A Cambridge Risk Score, B Kuwaiti Risk Score, C Omani Diabetes Risk Score, and D Simplified Finnish Diabetes Risk Score and E Rotterdam Predictive Model 1. Calibration describes the agreement between the probability of undiagnosed diabetes as estimated by the model and the recorded frequencies of the outcome. The ideal calibration is graphically represented by the dotted diagonal line at 45°. Participants are grouped into percentiles across increasing predicted risk. The vertical lines at the bottom of the graph depict the frequency distribution of the calibrated probabilities of diabetes. E/O, expected/observed ratio