Early versus delayed trial without catheter in men with Acute urinary retention - Study Protocol for a dutch national randomized trial

Introduction Acute urinary retention (AUR) is a burdensome urological emergency, often caused by benign prostatic obstruction. Standard management includes transurethral catheterization, alpha-blocker therapy, and a trial without catheter (TWOC) to assess spontaneous voiding. Despite the high incidence of AUR, the optimal catheter duration prior to TWOC remains uncertain. Evidence is limited, guideline recommendations are largely expert-based, and catheter duration varies widely in practice. Prolonged catheterization may increase morbidity and discomfort, whereas earlier removal may raise concerns regarding recurrent retention. Methods RELIEF is a pragmatic, multicenter, randomized non-inferiority trial comparing TWOC on day 3 versus TWOC on day 14 in men with AUR. All participants undergo transurethral catheterization and receive alpha-blocker therapy prior to randomization. Primary outcome is TWOC success, defined as a voided volume ≥100 mL and post-void residual ≤200 mL. The primary analysis follows a per-protocol approach, with a complementary intention-to-treat analysis to confirm non-inferiority. Secondary outcomes include recurrent retention, catheter-related complications, patient-reported symptoms and quality of life, and cost-effectiveness from healthcare and societal perspectives over 18 months. In parallel, a qualitative substudy using semi-structured interviews with healthcare professionals aims to explore the determinants underlying current practice variation, as well as the perceived barriers and facilitators for the sustainable implementation of a standardized TWOC strategy in future clinical practice. Discussion By comparing two catheterization intervals already applied in routine care and combining clinical, patient-reported, economic, and implementation outcomes, RELIEF is designed to generate directly applicable evidence on TWOC timing after AUR. The results are expected to support guideline refinement and improve consistency of care. Trial registration WHO ICTRP primary registry, identifier NL-OMON57836. Registered on February 7, 2025.