Comparison of Combination Therapy vs Single Agent Therapy for Treatment of Urge Incontinence.

This is a randomized double-blind placebo-controlled clinical trial of posterior tibial nerve stimulation (PTNS) plus extended release oxybutynin versus PTNS alone (placebo pills) in women undergoing treatment of urgency urinary incontinence (UUI). The investigators hypothesize that combination therapy with PTNS and anticholinergic medication will result in a significant incremental improvement in UUI symptoms over that achieved with PTNS alone. In addition, the investigators hypothesize that the addition of anticholinergics to PTNS will result in a greater improvement in patients' perception of treatment response, symptom distress, and quality of life than PTNS alone. Specific Aim 1: To compare the change, from baseline, in mean number of UUI episodes per day using a 3-day bladder diary between PTNS plus anticholinergic medication versus PTNS plus placebo in women undergoing treatment for UUI. Specific Aim 2: To compare the change, from baseline, in a 24hr pad weight between PTNS plus anticholinergic medication versus PTNS plus placebo. Specific Aim 3: To compare subjective treatment response, symptoms distress, and quality of life between PTNS plus anticholinergic medication versus PTNS plus placebo utilizing the Patient Global Impression of Improvement (PGI-I) and the Overactive Bladder Questionnaire Short Form (OABq-SF). An interim analysis will be conducted by an independent entity after 50 participants have completed the study protocol. A Data Safety Monitoring Board is not utilized because the study utilizes FDA approved treatments for urgency urinary incontinence.