Urethral Closure Pressure at Stress: A Predictive Measure for the Diagnosis and Severity of Urinary Incontinence in Women

PURPOSE: Maintaining urinary continence at stress requires a competent urethral sphincter and good suburethral support. Sphincter competence is estimated by measuring the maximal urethral closure pressure at rest. We aimed to study the value of a new urodynamic measure, the urethral closure pressure at stress (s-UCP), in the diagnosis and severity of female stress urinary incontinence (SUI). METHODS: A total of 400 women without neurological disorders were included in this observational study. SUI was diagnosed using the International Continence Society definition, and severity was assessed using a validated French questionnaire, the Mesure du Handicap Urinaire. The perineal examination consisted of rating the strength of the levator ani muscle (0–5) and an assessment of bladder neck mobility using point Aa (cm). The urodynamic parameters were maximal urethral closure pressure at rest, s-UCP, Valsalva leak point pressure (cm H(2)O), and pressure transmission ratio (%). RESULTS: Of the women, 358 (89.5%) were diagnosed with SUI. The risk of SUI significantly increased as s-UCP decreased (odds ratio [OR], 0.92; 95% confidence interval, 0.88–0.98). The discriminative value of the measure was good for the diagnosis of SUI (area under curve>0.80). s-UCP values less than or equal to 20 cm H(2)O had a sensitivity of 73.1% and a specificity of 93.0% for predicting SUI. The association between s-UCP and SUI severity was also significant. CONCLUSIONS: s-UCP is the most discriminative measure that has been identified for the diagnosis of SUI. It is strongly inversely correlated with the severity of SUI. It appears to be a specific SUI biomarker reflecting both urethral sphincter competence and urethral support.