 NC ProCESS is a population-based cohort designed specifically to address well-described knowledge gaps. It was designed in close collaboration with the unique AHRQ consortium stakeholder group, which included representatives from patients, clinicians and policymakers. Stakeholders helped define study design to emphasize real-world patients and select patient-centered and relevant outcomes, and have been involved throughout assembly of this patient cohort. The diverse cohort is well-represented by hard to reach patients; enrollment before treatment avoids biases with participation and recall. As clinical trials are not feasible to address the central questions in prostate cancer CER, this prospective study will yield the highest level of evidence to inform patients and other stakeholders. With an assembled cohort, this study is necessary to examine comparative outcomes. 