Fang Cheng, Jian Wang, Dongming Wang, Pengxiang Wang, Yunhe Zhang, Guoxin Song
OBJECTIVE: To estimate the added clinical benefit of extending transcutaneous tibial nerve stimulation (TTNS) from 12 to 24 weeks in pediatric overactive bladder (OAB), and to characterize late responders. PATIENTS AND METHODS: Prospective single-arm cohort with home-based TTNS and assessments at baseline, 12, and 24 weeks. The primary outcome was change in OAB Symptom Score (OABSS) and responder status defined by a minimal clinically important difference (MCID) of≥3 points. Paired responder transitions were tested with McNemar's exact test and summarized as paired risk difference (RD) with 10,000-sample bootstrap 95% CIs; repeated-measures GEE/LMM were pre-specified for confirmatory modeling. RESULTS: Among 80 paired observations, 12→24-week transitions were 0→0: 13, 0→1: 14, 1→0: 0, 1→1: 53. The paired RD in responder rate (24w-12w) was 0.175 (95% CI 0.100-0.263; McNemar p=0.000122). Late response occurred in 14 of 27 (51.9%) 12-week nonresponders. Mean OABSS improved by 3.64±2.25 at 12 weeks and 5.14±2.63 at 24 weeks. CONCLUSIONS: Extending TTNS to 24 weeks was associated with additional symptom improvement and a substantial proportion of late responders without loss of response. Findings suggest that continuing TTNS beyond 12 weeks may be considered for early nonresponders, pending confirmation in randomized, sham-controlled trials.