Early trajectories and re-evaluation windows after cessation of home-based transcutaneous tibial nerve stimulation in children with overactive bladder: A prospective cohort study

PURPOSE: To evaluate post-cessation response maintenance, symptom trajectories, and reassessment windows in children with idiopathic overactive bladder (OAB) who achieved clinical response after 12 weeks of home-based transcutaneous tibial nerve stimulation (TTNS). METHODS: This single-center prospective cohort study followed children receiving 12 weeks of home-based TTNS plus standard urotherapy. Post-cessation analyses were restricted to Week-12 responders because response maintenance could be evaluated only in children who had first achieved predefined response. Week-12 response was defined as an Overactive Bladder Symptom Score (OABSS) reduction of ≥3 points from baseline. Follow-up continued to Week 24 without active TTNS. Primary outcomes were Week-24 response maintenance and the visit distribution of first loss of predefined response; loss of predefined response was defined as an OABSS reduction of <3 points from baseline at a scheduled post-cessation visit. RESULTS: Among 142 evaluable children, 97 (68.3%) met Week-12 response criteria and formed the post-cessation study cohort. At Week 24, 67/96 (69.8%) remained in the predefined response state. During post-cessation follow-up, 33/97 children (34.0%) no longer met the predefined response criterion at least once. The first scheduled visit at which this occurred was most commonly within 8 weeks after TTNS cessation (Weeks 12-20). Mean OABSS decreased during treatment from 11.07 ± 2.31 at baseline to 5.37 ± 2.99 at Week 12 and then partially increased to 6.50 ± 3.49 at Week 24, while remaining below baseline. Children with Week-4 early response were less likely to experience first loss of predefined response (OR = 0.14, 95% CI 0.05-0.36), whereas children with higher Week-12 OABSS were more likely to experience this event (OR = 1.20, 95% CI 1.05-1.38). CONCLUSION: Clinical benefit after 12-week home-based TTNS generally persisted for several weeks after cessation, but Weeks 12-20 appeared to be the main observed window for detecting loss of predefined response and may help inform planned reassessment.