Subjective and objective responses to PTNS and predictors for success: a retrospective cohort study of percutaneous tibial nerve stimulation for overactive bladder

Abstract

We investigated the objective improvements in overactive bladder (OAB) symptoms in patients undergoing percutaneous tibial nerve stimulation (PTNS) and predictive factors of patient satisfaction. In this single-center retrospective cohort study at a tertiary urogynecology center, we identified all female patients who underwent PTNS therapy from 1 October 2007 - 1 January 2016 and followed them from their initial visit through medication therapy and PTNS treatments. Patients who tried at least one medication prior to starting PTNS therapy and completed at least one PTNS visit were included. Baseline demographic data, urinary data, and details of medication and PTNS therapy sessions were collected from records through chart review. Paired or two-sample t-tests were used to compare changes over time or groups. Bivariate and multivariable logistic regression were performed. Two hundred thirteen patients underwent PTNS therapy and 183 patients met the criteria. Overall patients were able to decrease voiding frequency by 1h, decrease nocturia episodes by 0.8, and decrease urge incontinence episodes with PTNS therapy by ten episodes per week (p = 0.02). Patients who continued OAB medications did not have additional improvements compared with patients who did not continue OAB medications during PTNS. Overall, 25.4% (43/169) patients reported ≥ 75% improvement during PTNS therapy, and 61.5% (104/169) reported ≥ 50% improvement. When evaluating predictive factors of ≥ 50% overall improvement, the number of PTNS sessions increased odds of subjective success (OR = 1.8, p = 0.004). Other factors were not significant predictors of subjective PTNS success. PTNS can provide both objective and subjective improvements for patients who do not respond to OAB medication therapy.