Fig. 2From: Development of a risk estimation model for condomless sex among college students in Zhuhai, China: a cross-sectional studyThe area under the receiver-operator characteristic curves (AUROC) and the calibration curve of the nomogram for predicting condomless sex. A The AUROC of Derivation cohort. B The calibration curve of Derivation cohort. C The AUROC of Validation cohort. D The calibration curve of Validation cohortBack to article page