Treatment Efficacy for Overactive Bladder: Comparing Education, Biofeedback, and Nerve Stimulation

Overactive Bladder (OAB) is a syndrome characterized by urinary urgency, often accompanied by frequency and nocturia, with or without urgency urinary incontinence. Detrusor overactivity is considered the most common underlying cause. Pelvic Floor Muscle Training (PFMT) is a standard first-line behavioral therapy that helps inhibit detrusor contractions by strengthening the pelvic floor.

This randomized controlled trial investigates the additive clinical value of biofeedback and neuromodulation on top of standard PFMT. Participants are stratified based on their clinical phenotype (OAB-wet or OAB-dry) and randomly assigned to one of three groups for an 8-week intervention period: Group 1 receives standard oral education on PFMT; Group 2 receives biofeedback-assisted PFMT to improve muscle contraction accuracy; and Group 3 receives biofeedback-assisted PFMT combined with percutaneous tibial nerve electrical stimulation. The neuromodulation intervention aims to inhibit involuntary detrusor contractions and regulate bladder nerve signals through peripheral nerve conduction.

All clinical interventions and assessments are conducted in a dedicated, private biofeedback treatment room. Participants are scheduled for in-person clinic visits at weeks 0, 2, 4, and 8. During these visits, participants in Groups 1 and 2 will undergo routine assessment and muscle contraction quality checks lasting 30 to 40 minutes. Participants in Group 3 will additionally receive a 30 to 40-minute session of tibial nerve electrical stimulation (parameters: 20 Hz, 200 μs, with intensity adjusted to the maximum tolerable painless threshold).

In addition to clinic visits, all participants are required to perform daily home-based PFMT. They will track their exercise frequency and compliance using a dedicated smartphone timer application. The study seeks to provide evidence for personalized clinical treatment decisions by analyzing which level of intervention yields the best symptom relief and quality of life improvement for different OAB phenotypes.

• Behavioral (Behavioral): Participants receive standard oral education on Pelvic Floor Muscle Training (PFMT). They are instructed to perform daily home-based pelvic floor exercises and track their compliance and exercise frequency using a smartphone timer application. Clinical assessments and educational reinforcements are conducted at weeks 0, 2, 4, and 8.
• Enraf-Nonius EMG-Biofeedback Unit (Biofeedback only) (Device): Participants undergo biofeedback-assisted Pelvic Floor Muscle Training (PFMT) using the Enraf-Nonius EMG-Biofeedback Unit. During clinic visits at weeks 0, 2, 4, and 8, the device is used to assist patients in accurately identifying and contracting the correct pelvic floor muscles. In addition to clinic sessions, participants perform and track daily home-based PFMT.
• Enraf-Nonius EMG-Biofeedback Unit (Biofeedback + Electrical Stimulation) (Device): Participants receive biofeedback-assisted PFMT combined with percutaneous tibial nerve electrical stimulation using the Enraf-Nonius device. During clinic visits at weeks 0, 2, 4, and 8, patients receive a 30 to 40-minute session of electrical stimulation (parameters: 20 Hz, 200 μs, with intensity progressively adjusted to the maximum tolerable painless threshold). Participants also perform and track daily home-based PFMT.

Primary outcomes

• Change in Overactive Bladder Symptom Score (OABSS) [Baseline (Week 0), Week 2, Week 4, and Week 8]: he OABSS is a validated, self-administered questionnaire used as a core clinical scale to evaluate the severity of overactive bladder symptoms. It consists of four items: daytime frequency, nighttime frequency, urgency, and urgency incontinence. The total score is calculated by summing the scores of the four items, with a higher total score indicating more severe OAB symptoms. The primary endpoint will evaluate the change in the total score from baseline to the end of the 8-week intervention.
• Change in 3-day Bladder Diary Parameters [Baseline (Week 0) and Week 8]: Participants will record their voiding habits over a 72-hour period, including fluid intake, number of micturitions (frequency), and number of urinary incontinence episodes.

Secondary outcomes

• Change in Overactive Bladder Questionnaire (OAB-q) Score [Baseline (Week 0), Week 2, Week 4, and Week 8]: Pelvic floor muscle function will be assessed using the biofeedback device to measure vaginal pressure or by manual muscle testing (MMT) to evaluate the change in pelvic floor muscle strength.
• Change in King's Health Questionnaire (KHQ) Score [Baseline (Week 0), Week 2, Week 4, and Week 8]: This questionnaire evaluates the impact of urinary incontinence on the physical, psychological, and social dimensions of the participants' health-related quality of life.
• Subjective Symptom Improvement Rating [Baseline (Week 0), Week 2, Week 4, and Week 8]: A patient-reported outcome measure where participants subjectively score their overall degree of symptom relief throughout the intervention period
• Change in Pelvic Floor Muscle Strength [Baseline (Week 0), Week 2, Week 4, and Week 8]: Pelvic floor muscle function will be objectively assessed using the biofeedback device to measure vaginal pressure or by manual muscle testing (MMT) to evaluate the change in muscle strength.
• Change in PFMT Self-Efficacy and Home Exercise Compliance [Baseline (Week 0), Week 2, Week 4, and Week 8]: This measure quantifies patients' psychological readiness and persistence in performing pelvic floor muscle training (PFMT). It is combined with the objective monitoring of their daily home exercise frequency, which is tracked using a smartphone timer application.

Sex: Female, ages: 20 Years to any

Inclusion Criteria:

* Stable on chronic medications: Participants must have been on a long-term, regular regimen of routine medications for chronic conditions (e.g., hypertension, diabetes, hyperlipidemia) prior to study entry, with no expected changes in dosage or administration during the 8-week study period.
* Diagnosed with Overactive Bladder (OAB) according to the International Continence Society (ICS) definition, including urgency, frequency, and nocturia, with or without urgency urinary incontinence (must be documented as OAB-wet or OAB-dry).
* Symptoms persisting for at least 3 months.
* Overactive Bladder Symptom Score (OABSS) total score ≥ 3 at baseline (Week 0), with an urgency score (Question 3) ≥ 2 (meeting the clinical threshold for core OAB symptom intensity).

Exclusion Criteria:

* Concurrent active urinary tract infection (UTI), bladder stones, or urinary tract malignancy.
* Inability to follow instructions for muscle training due to cognitive impairment or severe psychiatric illness.
* Presence of implanted electronic medical devices (e.g., cardiac pacemakers) (contraindication for electrical stimulation).
* Currently pregnant women or those planning to become pregnant during the study period.
* Use of antimuscarinics (e.g., Oxybutynin, Tolterodine, Solifenacin) or beta-3 adrenergic receptor agonists (e.g., Mirabegron) within 2 weeks prior to study entry.
* Receipt of pelvic or perineal physical therapy outside of this study protocol (e.g., vaginal or anal probe electrical stimulation, pelvic floor magnetic stimulation, transcutaneous microcurrent stimulation) within 2 weeks prior to study entry.
* Receipt of intravesical Botulinum toxin (Botox) injections, sacral neuromodulation, or any surgical treatment related to urinary incontinence or pelvic organ prolapse within 2 weeks prior to study entry.

• Wen Yih Wu, MD, Principal investigator, Far Eastern Memorial Hospital