To identifysite variability in eligibility screening, the most effective approach is toplot eligibility rate by site. This allows visual detection of differences in how well each site screens subjects according to protocol-defined inclusion and exclusion criteria.

TheGCDMP (Chapter: Data Quality Assurance and Metrics)emphasizes the importance of graphical analysis for identifying anomalies and site-level performance variability. By plotting the eligibility rate by site, data managers and clinical operations teams can quickly identify outliers—sites that screen too many or too few eligible subjects—indicating potential training issues, misunderstanding of inclusion/exclusion criteria, or even possible protocol deviations.

While summarizing screening rate (B) provides useful numeric data, it lacks visual comparability. Listing waivers (A) or enrollment counts (C) provide limited insights intoeligibility consistency.

Therefore,option D—Plot eligibility rate by site—is the best analytic and visualization practice to assess site variability in screening outcomes.

Reference (CCDM-Verified Sources):

SCDM GCDMP, Chapter: Data Quality Assurance and Control, Section 6.1 – Use of Metrics and Graphical Review for Site Performance

ICH E6(R2) GCP, Section 5.18.4 – Identification of Systematic or Site-Specific Issues