Post-void residual urine volume in women with overactive bladder symptoms

Most patients with overactive bladder symptoms initially present to their primary care provider for treatment. It is currently recommended that post-void residual urine (PVR) should be measured during the assessment of women complaining of overactive bladder symptoms and anticholinergic medication should be used if PVR is low. However, many primary care providers are reluctant to measure PVR and, therefore, they may delay treatment or even inappropriately treat patients who have a high PVR. We identified clinical factors that are associated with increased PVR that could be used to select which patients are at risk for this.

The charts of women presenting to our clinic with complaints of urinary frequency, urgency and/or urge incontinence were retrospectively reviewed. Patient demographics, physical examination and PVR were analyzed to determine if any factor was associated with increased PVR (100 ml or greater).

The charts of 201 patients with complete data were reviewed. Patient age was 20 to 90 years (mean 55). Overall 19% of patients were found to have elevated PVR. Univariate analysis identified that older age, prior incontinence surgery, history of multiple sclerosis, greater American Urological Association Symptom Score, vaginal parity greater than 2, greater pad use and stage 2 or greater vaginal prolapse were associated with elevated PVR. Multivariate analysis identified age older than 55 years, prior incontinence surgery, a history of multiple sclerosis and vaginal prolapse stage 2 or greater as independent predictors of elevated PVR.

It is possible to identify patients with overactive bladder symptoms who are at risk for elevated PVR based on history and physical examination. This could result in fewer patients needing PVR measurement prior to initiating treatment.