Fig. 3. Receiver operating characteristic and case probability density plots in the external dataset (PDBP) at validation for the trained and then tuned models at default thresholds.

Probabilities are predicted case status (r1), so controls (status of 0) skews towards more samples on the left, and positive PD cases (status of 1) skews more samples on the right. a Testing in PDBP the combined *omics model (genetics p value threshold = 1E-5, transcriptomics p value threshold = 1E-2, and clinico-demographic information) developed in PPMI prior to tuning the hyperparameters of the model; b Testing in PDBP the combined *omics model (genetics p value threshold = 1E-5, transcriptomics p value threshold = 1E-2, and clinico-demographic information) developed in PPMI after tuning the hyperparameters of the model. PPMI Parkinson’s progression marker initiative, PDBP Parkinson’s disease biomarker program, ROC receiver operating characteristic curve.