Optimize PTSD Diagnostic Criteria // Provides tools for analyzing and optimizing PTSD (Post-Traumatic Stress Disorder) diagnostic criteria using PCL-5 (PTSD Checklist for DSM-5) and CAPS-5 (Clinician-Administered PTSD Scale for DSM-5) data. Functions identify optimal subsets of PCL-5 items that maintain diagnostic accuracy while reducing assessment burden. Includes tools for both hierarchical (cluster-based) and non- hierarchical symptom combinations, calculation of diagnostic metrics, and comparison with standard DSM-5 criteria. Redundancy analysis quantifies how many item subsets perform equivalently, through plateau sizes and bootstrap stability, and reports item selection against the chance baseline of the searched candidate space. A transport layer allows a site to evaluate subsets derived elsewhere and return only aggregate summaries, supporting multi-site validation without sharing individual-level data. Model validation is conducted using holdout and cross-validation methods to assess robustness and generalizability of the results. For more details see Weidmann et al. (2025) doi:10.31219/osf.io/6rk72_v1.