Search results for "Optimal cutoff"
showing 3 items of 3 documents
PSA and PSA Kinetics Thresholds for the Presence of 68Ga-PSMA-11 PET/CT-Detectable Lesions in Patients with Biochemical Recurrent Prostate Cancer
2020
68Ga-PSMA-11 positron-emission tomography/computed tomography (PET/CT) is commonly used for restaging recurrent prostate cancer (PC) in European clinical practice. The goal of this study is to determine the optimum time for performing these PET/CT scans in a large cohort of patients by identifying the prostate-specific-antigen (PSA) and PSA kinetics thresholds for detecting and localizing recurrent PC. This retrospective analysis includes 581 patients with biochemical recurrence (BC) by definition. The performance of 68Ga-PSMA-11 PET/CT in relation to the PSA value at the scan time as well as PSA kinetics was assessed by the receiver-operating-characteristic-curve (ROC) generated by plottin…
Overrating Classifier Performance in ROC Analysis in the Absence of a Test Set: Evidence from Simulation and Italian CARATkids Validation
2019
Background The use of receiver operating characteristic curves, or “ROC analysis,” has become quite common in biomedical research to support decisions. However, sensitivity, specificity, and misclassification rates are still often estimated using the training sample, overlooking the risk of overrating the test performance. Methods A simulation study was performed to highlight the inferential implications of splitting (or not) the dataset into training and test set. The normality assumption was made for the classifier given the disease status, and the Youden's criterion considered for the detection of the optimal cutoff. Then, an ROC analysis with sample split was applied to assess the disc…
Optimal carbohydrate antigen 125 cutpoint for identifying low-risk patients after admission for acute heart failure
2022
Introduction and objectives: Carbohydrate antigen 125 (CA125) has been shown to be useful for risk stratification in patients admitted with acute heart failure (AHF). We sought to determine a CA125 cutpoint for identifying patients at low risk of 1-month death or the composite of death/HF readmission following admission for AHF.Methods: The derivation cohort included 3231 consecutive patients with AHF. CA125 cutoff values with 90% negative predictive value (NPV) and sensitivity up to 85% were identified. The adequacy of these cutpoints and the risk of 1-month death/HF readmission was then tested using the Royston-Parmar method. The best cutpoint was selected and externally validated in a co…