Next, we quantified the effect of adding CTCS to the model on the classification of patients into probability categories of CAD. Four probability categories were defined: <30%, ≥30–50%, ≥50–70% and ≥70%. Reclassification tables were constructed for the Diamond & Forrester model and the Pryor model (see Tables 4 and 5) [19]. We computed the reclassification calibration statistic (RCS) [20] which is equivalent to the Hosmer–Lemeshow statistic, applied to the cross-classified cells of the reclassification table with at least 20 observations. A significant result indicates a lack of fit.