Male urinary incontinence (UI) is a complex condition with diverse etiologies and variable severity, particularly in men with a history of pelvic surgery, radiation, or neurogenic dysfunction. Existing classification systems do not adequately reflect these multidimensional factors, limiting their utility in guiding treatment. We hypothesize that a new classification (MI-CRONS) combining etiology and severity of male UI, will enhance diagnostic precision and therapeutic decision-making. The aim of this study is to apply the MI-CRONS classification in a clinical setting to systematically describe and stratify patients with male urinary incontinence.

We conducted a single-center observational study involving 157 male patients with UI treated between March 2020 and January 2025. The MI-CRONS classification integrates:
Etiology:
C – cancer surgery (radical prostatectomy)
R – radiation therapy
O – outlet obstruction surgeries (e.g., TURP)
N – neurogenic/non-neurogenic bladder dysfunction
S – urethral strictures
These codes may be combined (e.g., CR, CORS, RN).
Severity: graded from 1 (mild) to 4 (total), based on: 24-hour pad test, preservation of voluntary voiding, number of pads used, physical effort triggering incontinence, and presence of nocturnal enuresis.
In a prospective subset of 21 patients, additional assessments included the ICIQ-MLUTS questionnaire, 3-day voiding diary, urinalysis, and urodynamic studies (cystometry and pressure-flow test). Correlation between MI-CRONS severity and objective pad weight test was evaluated using Spearman’s ρ.

Out of 157 patients with male urinary incontinence, 156 (99.4%) were successfully classified using the MI-CRONS system. The most frequently observed combinations included CR2 (patients after radical prostatectomy and radiation therapy with moderate incontinence) and CORS3 (patients with prior surgery, radiation, urethral stricture, and severe incontinence). The classification covered a wide spectrum of clinical presentations, from mild stress incontinence to total incontinence with complete loss of voluntary voiding.

In a prospective subgroup of 21 patients, the MI-CRONS classification correlated well with 24-hour pad test volumes and symptom severity reported in ICIQ-MLUTS. Patients with grade 1 and 2 typically reported minimal use of pads and preserved spontaneous voiding, whereas those classified as grade 4 required continuous external collecting devices and demonstrated high leakage volumes. The classification allowed for clear stratification based on both etiology and severity, facilitating the identification of patients requiring conservative versus surgical management.

MI-CRONS integrates etiological complexity and severity of male urinary incontinence into a concise, clinically intuitive framework. It enables structured assessment of patients and supports individualized decision-making by aligning classification profiles with common treatment approaches. The system proved easy to apply in clinical practice and helped standardize communication across diverse patient presentations.

The MI-CRONS classification offers a comprehensive, simple, and clinically useful system for evaluating male urinary incontinence. It supports personalized care based on cause and severity. Further multicenter validation is needed to confirm its broader applicability and prognostic value.

Kasyan, G., Grigoryan, B., & Pushkar, D. (2024). A novel clinical classification for male urinary incontinence: MI-CRONS. Continence Reports, 10, 100051.