Successfull trial without catheter development of a clinical nomogram

INTRODUCTION AND OBJECTIVE: Aim of our study was to evaluate predictors of successfull trial without catheter (TWOC) in a consecutive series of patients with acute urinary retention (AUR) and develop a clinical nomogram METHODS: Between April 2017 to April 2019 a consecutive series of patients with AUR were consecutively enrolled in three centers. For each patient medical history, uroflowmetry and IPSS up to 6 months from AUR were evaluated. Urinary tract ultrasound was performed to evaluate hydronefrosis. Prostate Volume (TRUS) and Intravescical Prostatic Protrusion (IPP) at the AUR time. TWOC was performed seven days after AUR after starting alpha-blockers treatment. A nomogram was developped with significant predictors of AUR. Performance of the nomogram was assessed with receiver operator characteristics (ROC) curve, calibration plots and decision curve analysis (DCA). Internal validation with 200 bootstrap was performed RESULTS: Overall 161 patients were enrolled with a median age of 71 years (64/77). Successfull TWOC seven days after AUR was achieved in 92/161 (57%) patients. Patients with successfull TWOC presented higher IPSS scores, PV and IPP score when compared to patients who failed TWOC. On age adjusted multivariate logistic regression IPSS (OR: 0,93 95%CI:0,87-0,98, p=0,01), PV (OR:0,98 95%CI:0,97-0,99) and IPP (OR:0,35 95%CI:0,15-0,84) were independent predictors of successfull TWOC. A nomogram was developped based on the multivariate analysis. Discrimination assessed on ROC analysis showed an AUC=0,82, calibration assessed by the Hosmer lemeshow test was good (p=0,35) and the nomogram presented a net benefit in the range of probabilities between 40 and 70%. Internal validation after 200 bootstrap showed an AUC of 0,81 CONCLUSIONS: Patients with acute urinary retention present a 57% probability of a successfull trial without catheter. Our nomogram, internally validated, showed excellent discrimination properties and could help in the counseling of patients with AUR before TWOC. External validation is needed before clinical implementation