Comparison of the Efficacy of Transcutaneous Tibial Nerve Stimulation in Antimuscarinic Naive and Refractory Women With Idiopathic Overactive Bladder

This study was planned as a prospective clinical trial. The trial was carried out in the Urogynecological Rehabilitation Unit of Physical Medicine and Rehabilitation Department, in between January 2023 and June 2023. The local ethics committee approved the study. All women were informed about the purpose and contents of the study and all women signed written consent to participate in the study.

As previously published by Sonmez et al , BT+IVES succeeded to reduce mean incontinence episodes from 4.40±3.43 to 0.70±0.57 after treatment in the active comparator group while mean incontinence episodes was reduced from 4.15±1.67 to 2.68±1.66 after treatment in the control group (BT). Considering a 50% or greater improvement in incontinence episodes in the referred study, the optimum sample size should be 18 cases in each arm with a level of significance of 95% (α=5%), a power of 95% (ß=0.05) . Taking into account possible withdrawals which was assumed to be about 10% of the number of patients, a total of 40 women (20 women for each group) were calculated for this study. Sample size calculation was performed by the physician using G*Power 3.1 Statistical Power Analysis for Microsoft Windows and Mac. Statistics.

To investigators recruited women with complaints of OAB who were referred to the Urogynecological Rehabilitation Unit and other related outpatient clinics. Women over the age of 18 with the clinical diagnosis of idiopathic OAB, and who could able to give written informed consent and understand the procedures were included in this study. The criteria for exclusion were as follows. Women who had stress urinary incontinence; a history of PTNS and/or TTNS 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 or posttraumatic malformations/skin disorders of tibial nerve region on inner ankle that can not allow to apply the electrodes; 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 were excluded.

Women with idiopathic OAB were recruited for eligibility and of them who fulfilled the inclusion/exclusion criteria were included for this study. Antimuscarinic naive women were included in Group 1 (n:20), and women resistant to anti-muscarinic agents were included in Group 2 (n:20). Both groups received BT plus TTNS.

Group 1: Antimuscarinic Naive (AM-N) None of the women had previously taken anti-muscarinic agents and oral ß3 adrenoreceptor agonist (mirabegron) in this group.