Defining the Safety and Efficacy of POSterIor Tibial NeRve StimulatiON in Children

The frequency of select safety Events of Special Interest.

1. Electrode site reaction (bruising, bleeding, hematoma, or persistent erythema at the electrode site) 2. Electrode site infection 3. Repeated post-void residual \>60 mL (at ≥ 2 consecutive visits) 4. Urinary tract infection 5. Urinary retention/obstruction 6. Toe numbness 7. Stomach and leg cramps

Change in maximum voided volume on the Bladder Diary

The Bladder Diary is a paper diary recommended by the International Children's Continence Society that will be completed by the parent/guardian/LAR or participant. The Bladder Diary includes the following variables: fluid intake, number of voids, volume of voids, degree of urgency, number of incontinent episodes.

Proportion of children who experienced complete response, no response, or partial response on the Vancouver Dysfunctional Elimination Survey (VDES)

The VDES is a validated questionnaire that was developed for diagnosing dysfunctional elimination syndrome. The survey uses a five-point Likert scale to score symptoms of bladder dysfunction. Each question is scored on a scale of 0-4, with 0 indicating no complaints and 4 indicating severe symptoms. The total score ranges from 0-52, with higher scores indicating more severe symptoms. The question about voiding frequency is scored differently from the other questions. A neutral choice of five to six urination per day is scored as 0. A urinary frequency of one to two times or more than eight times a day is scored as 4. A urinary frequency of three or four and seven or eight times a day is scored as 2. A cutoff score of 11 is used for patients and 9 for parents to diagnose dysfunctional voiding. The VDES is completed by the parent/legal guardian if participants are \< 9 years old and by participants if they are ≥ 9 years old.

Change in OAB symptoms (Urgency, Frequency and Daytime Incontinence) reported on the VDES

Change in OAB symptoms will be evaluated from the symptom questions on the VDES survey assessing Urgency, Frequency and Daytime Incontinence. The survey uses a five-point Likert scale to score symptoms of bladder dysfunction. Each question is scored on a scale of 0-4, with 0 indicating no complaints and 4 indicating severe symptoms. The total score ranges from 0-52, with higher scores indicating more severe symptoms. The question about voiding frequency is scored differently from the other questions. A neutral choice of five to six urination per day is scored as 0. A urinary frequency of one to two times or more than eight times a day is scored as 4. A urinary frequency of three or four and seven or eight times a day is scored as 2. A cutoff score of 11 is used for patients and 9 for parents to diagnose dysfunctional voiding. The VDES is completed by the parent/legal guardian if participants are \< 9 years old and by participants if they are ≥ 9 years old.

Proportion of children who develop a febrile UTI

Febrile UTI occurrence, defined as: • Fever \> 101.5°F (\> 38.6°C); and \>50,000 colony forming units (CFU)/mL of 1 or more speciated organisms; and 10 white blood cells per higher power field (WBC/HPF) on urine microscopy and/or leucocyte esterase \> 2+ on dipstick; and At least 1 of the following symptoms: Gross hematuria (defined as pink or red urine, not a spot of blood on a catheter) OR Abdominal, suprapubic, or flank pain or tenderness OR New or worsening incontinence OR New or worsening urinary urgency, frequency, or hesitancy OR Nausea/vomiting OR Pain with urination OR Malodorous/cloudy urine.

The change of Pediatric Incontinence Quality of Life (PINQ) score

The Pediatric Incontinence Quality of Life (PINQ) is a 20-item, self-reported questionnaire that evaluates the QoL of children who have urinary incontinence. Each item is scored on a 5-point Likert scale, with 1 being "no" and 5 being "always". The total score ranges from 20 to 100 points. A higher score indicates a better QoL that is less affected by urinary symptoms. The PINQ is validated for use in children 6-17 years old and has been used in studies of participants up to 30 years old.21,25 The PINQ will be completed by the parent/legal guardian/LAR if participants are \< 9 years old and by participants if they are ≥ 9 years old.