Risk Factors for Severe Hypocalcemia in Patients with Secondary Hyperparathyroidism after Total Parathyroidectomy

Figure 2

ROC curves for postoperative severe hypocalcemia by the binary logistic regression equation. This graph shows the ROC curves for preoperative Lg-iPTH (blue), Lg-ALP (green), and Model-SH (red). The prognostic factors in Model-SH include preoperative serum calcium, iPTH, and ALP. AUC for Lg-iPTH and Lg-ALP were 0.812 and 0.837, respectively. The cut-off values for Lg-iPTH and Lg-ALP were 3.21 and 2.32, respectively. AUC for Model-SH was 0.875 and the cut-off value was 3.25. The sensitivity and specificity of Lg-iPTH were 78.9% and 70.7%, respectively. The sensitivity and specificity of Lg-ALP were 90.5% and 64.7%, respectively. The sensitivity and specificity of Model-SH were 90.8% and 71.9%, respectively. Predictor = 0.738  Lg-ALP + 1.205  Lg-iPTH − (albumin − adjusted calcium) (all of the indexes were preoperative).