Are there differences between women with urge predominant and stress predominant mixed urinary incontinence?

We sought to determine if there are differences in clinical and urodynamic parameters between women with urge predominant and those with stress predominant mixed urinary incontinence (MUI).

Charts of 99 female patients with complaints of MUI were reviewed. Patients were divided into two groups based on the subjective predominance of either stress incontinence (MSUI) or urge incontinence (MUUI). All patients completed a subjective evaluation including an AUA Symptom Index, Urogenital Distress Inventory (UDI-6), and Incontinence Impact Questionnaire (IIQ-7). Objective non-invasive measures included physical exam, 48-hr voiding diary, and a 24-hr pad test. Videourodynamics studies (VUDS), performed in all patients, were reviewed and the presence and characteristics of detrusor overactivity (DO) and stress incontinence were noted.

There were no significant differences between groups with respect to symptom scores. MUUI patients had significantly higher pad usage, and lower maximum and average voided volumes than MSUI patients. They were also more likely to have lower urodynamic bladder capacities and demonstrable DO (70% vs. 26%) on VUDS with contractions occurring at lower bladder volumes and with higher amplitude. MSUI patients were more likely to have demonstrable SUI on physical examination (63% vs. 16%) and on VUDS (100% vs. 61%).

There do appear to be differences in clinical and urodynamic parameters between patients with stress predominant and urge predominant MUI. These may help to determine which component of the mixed incontinence is more problematic.