Urgency urinary incontinence (UUI), involuntary loss of urine associated with urgency, constitutes 22% of urinary incontinence (UI) in women [1]. It negatively affects the quality of life (QoL) [1]. To reduce detrusor overactivity, inhibit sensory sensitivity and increase bladder compliance, conservative treatments such as lifestyle advices, bladder training, pelvic floor muscle exercise (PFME) and electrical stimulation (ES) can be used [1]. According to the guidelines, lifestyle advices are considered as a method, added to the treatment of UUI [2]. Neuromuscular electrical stimulation (NMES) can be used to improve sensorial awareness, muscle reeducation and circulation [3]. Transcutaneous NMES applications are basically divided into two, internal (IES) and external ES (EES). It has been observed that external NMES devices, known as novel EES, are more preferred than IES [3]. There are few studies examining the effects of NMES in overactive bladder (OAB) accompanied by UUI and in UUI with a neurogenic bladder. However, high methodological quality studies are needed to examine the effects of external NMES in patients with UUI. Therefore, the current study aimed to examine the effects of external NMES on urinary symptoms, pelvic floor muscle strength (PFMS), QoL, sexual function, perception of subjective improvement (PSI), and satisfaction in women with UUI.

A randomized sham-controlled study was conducted between July 2021 and December 2022  . Volunteer women aged 18-65 years who were newly diagnosed with UUI were included. Pregnancy, urinary infection, advanced pelvic organ prolapse, mixed urinary incontinence, neurological disease, cardiac arrhythmia, using electronic/metal implants or pacemaker, malignant disease, and loss of sensation were excluded from the study. Written consent forms were obtained. Patients were randomly allocated into the NMES (external NMES+lifestyle advice, n=15) and sham groups (sham NMES+lifestyle advice, n=15). The application (figure 1) was applied for 30 minutes, three days a week for eight weeks in both groups. 
Urinary symptoms were evaluated with the International Incontinence Consultation Questionnaire-Short Form (ICIQ-SF) and a 3-day bladder diary. PFMS, QoL, sexual function were assessed with the Modified Oxford Scale (MOS), the King’s Health Questionnaire (KHQ), and the Pelvic Organ Prolapse/Urinary Incontinence Sexual Function Questionnaire (PISQ-12), respectively. All assessments were evaluated by the same therapist before treatment (BT), mid-term (MT, 4th week), and after treatment (AT, 8th week). AT, PSI and satisfaction level of patients were also questioned  .
G*Power (v.3.9.1.7) program was used to determine sample size. A pilot study on 10 women found effect sizes for ICIQ-SF, MOS, KHQ-incontinence effect, and PISQ-total scores as 0.675, 0.670, 0.519, and 0.557, respectively. A minimum of 14 patients per group was needed at 90% power (α=0.05, β=0.10). An additional 20% of patients were added to account for data losses, resulting in a total of at least 34 patients for the study.

Mixed ANOVA was used to analyze the effects of the group factor (NMES and sham group), time factor (BT, MT, and AT), and their interaction. Pairwise comparisons for the time factor were conducted using the Bonferroni method. The Chi-square test was used for categorical variables. Analysis was performed using IBM SPSS Statistics 21.0, with statistical significance set at p<0.05.

For eligibility of the study, 44 patients were evaluated. Thirty patients completed the study. No adverse effect during the applications was reported. 
There was a decrease of the ICIQ-SF scores was found between BT and AT in the sham group while a greater decrease in the ICIQ-SF scores in the NMES group at all times (p<0.05, Table 1).  The sham group only showed a decrease in the mean number of UI (p<0.05). The NMES group had a greater decrease in voids/night and UI, and a greater increase in maximum voiding volume compared to the sham group (p<0.05, Table 1). No improvement was found in the sham group in MOS scores (p>0.05). A greater increase in MOS scores was observed in the NMES group compared to the sham group (p<0.05, Table 1). In the sham group, no change was seen in KHQ scores (p>0.05). There was a greater decrease in KHQ scores (excluding interpersonal relationships) in the NMES group than the sham group (p<0.05, Table 2). In the sham group, no improvement was detected in PISQ-12- physical, emotional, partner dependent and total scores (p>0.05). There was a higher increase in PISQ-12 scores (excluding partner dependent score) in the NMES group than the sham group (p<0.05, Table 1).
In the NMES group, 60.0% of individuals said they were better and 40.0% said they were completely healed, while in the sham group, 53.3% said they were the same, 40.0% said they were better, and 6.7% said they were fully recovered. There was a significant relationship between the groups in terms of patient satisfaction and compliance with advice, with higher satisfaction reported in the NMES group. There was no significant difference in compliance between the two groups.

The current study put forward that the NMES group was seen to be more effective in reducing urinary symptoms and improving PFMS, QoL, sexual function, PSI, and patient satisfaction level than the sham group. There was a greater improvement in some urinary symptoms, PFMS, QoL, and sexual function in the NMES group in the early period (MT-4th week) than the sham group. In the sham group, only urinary symptoms improved in the MT and AT.

External NMES was more effective in reducing urinary symptoms and improving PFMS, QoL, sexual function, PSI, and satisfaction level in women with UUI compared to sham.

Nandy S, Ranganathan S. Urge Incontinence. In:StatPearls. Treasure Island (FL): StatPearls Publishing. 2022;33085319.
Imamura M, Williams K, Wells M, McGrother C. Lifestyle interventions for the treatment of urinary incontinence in adults. Cochrane Database Syst Rev. 2015;2(12). https://doi.org/10.1002/14651858.CD003505.pub5.
Weil EH, Matzel K. Electrical stimulation for pelvic floor disorders. Martellucci J, (ed). Springer International Publishing. 2015. https://doi.org/10.1007/978-3-319-06947-0_1.

Continence 12S (2024) 101618
DOI: 10.1016/j.cont.2024.101618