In this study, it was aimed to compare the effectiveness of intravaginal electrical stimulation (IVES) added to bladder training (BT) on quality of life (QoL) and clinical parameters related to overactive bladder (OAB) in antimuscarinic naive and refractory women. The results of this study would make it easier to understand the place of IVES among the treatment options in women with idiopathic OAB.

Overactive bladder (OAB) is a symptom complex defined as urgency, with or without urgency urinary incontinence (UUI), usually with frequency and nocturia in the absence of urinary tract infection. Some authors listed the treatment options in idiopathic OAB as follows; first-line - behavioral therapy (lifestyle modifications, pelvic floor muscle (PFM) training, bladder training (BT), timed voiding), second-line - pharmacologic (antimuscarinic, beta-3 agonists), and third-line - neuromodulation/chemodenervation (tibial nerve stimulation, sacral neuromodulation, intradetrusor botulinum toxin). Intravaginal electrical stimulation (IVES) is involved in pelvic floor muscle training as a first-line treatment option. On the contrary, some authors stated that "the first-line treatment of idiopathic OAB includes behavior modification and physical therapy, and neuromodulation methods are used as third-line therapy in cases refractory to first-line and second-line (pharmacological) treatment. IVES, tibial nerve stimulation, and sacral neuromodulation are included as neuromodulation options". However, it is known that many patients with idiopathic OAB receive pharmacological treatment before reaching a conservative treatment option such as IVES. In common practice, antimuscarinic agents are frequently used as an initial treatment although burdened by a low adherence, and these patients need protracted treatment with periodic controls.

Some studies included subjects were not used antimuscarinics within the last 4-12 weeks or antimuscarinic-naive patients with OAB, while some included patients with OAB who were unresponsive or intolerant to antimuscarinics. As a result, IVES appear to be effective therapies used both as first-line treatment, as well as in managing refractory patients with idiopathic OAB. There is no evidence that it is most effective in which patients (antimuscarinic naive and refractory). Would it be more effective on the first-line or the third-line? or in other words; is there a difference in response to IVES in antimuscarinic naive and refractory patients with OAB? It should be kept in mind that IVES may lead to different results in antimuscarinic naive and refractory patients with idiopathic OAB. This study is the first prospective trial that compares the efficacy of IVES in antimuscarinic naive and refractory women with idiopathic OAB. In this study, it was aimed to compare the effectiveness of IVES added to BT on quality of life (QoL) and clinical parameters related to OAB in antimuscarinic naive and refractory women. The results of this study would make it easier to understand the place of IVES among the treatment options in women with idiopathic OAB.

Inclusion Criteria:

• Over the age of 18 with the clinical diagnosis of idiopathic OAB
• Who could able to give written informed consent and understand the procedures

Exclusion Criteria:

• Women who had stress urinary incontinence
• A history of conservative therapy (BT, ES) for OAB within 6 months
• Urogynecological surgery within 3 months
• Current vulvovaginitis or urinary tract infections or malignancy
• Pregnancy
• Cardiac pacemaker or implanted defibrillator
• Anatomic structural disorders of the genital region that did not allow to apply the vaginal probe
• The strength of PFM less than 3/5 (graded as modified Oxford scale, min:0-max:5)
• The pelvic organ prolapse quantification (POP-Q) (stage 2 or more)
• Neurogenic bladder
• The peripheral or central neurologic pathology
• Ultrasonographic evidence of post-void residual urine volume more than 100 ml
• Allergy to condom or lubricant gel that is used with vaginal probe