Third line interventions for overactive bladder (OAB) are indicated for patients that fail behavioural and pharmacological therapies. These include percutaneous tibial nerve stimulation (PTNS), sacral neuromodulation (SNM) and intradetrusor onabotulinum toxin injection. The aim of this study is to identify predictors of progression to alternate 3rd line treatment options following PTNS in patients with OAB refractory to medical and behavioural therapy.

This study is a retrospective cohort analysis of patients that underwent PTNS between March 2018- June 2023 for management of overactive bladder. The primary outcome of this study was progression to alternate 3rd line treatment options following PTNS, such as SNM or intradetrusor onabotulinum toxin injections. The secondary outcome of this study was continuation with maintenance therapy following initial 12-week PTNS treatment course.

A total of 49 patients were included for analysis. Overall, 33% (16/49) of patients had further alternate 3rd line treatment. Patients that underwent additional treatment following PTNS were significantly younger compared to those that did not (p=0.047). Of the patients that pursued alternative treatment options, there was a significantly greater proportion of patients with diabetes (p=0.009) compared to those that did not. Univariate analysis identified a significant correlation between younger age, history of diabetes, previous onabotulinum toxin injection, with progression to further 3rd line treatment. Multivariate logistic regression analysis identified only age (OR=1.04; p=0.032) as a significant predictor of progression to alternate 3rd line OAB treatment following PTNS. Patients who completed more of the 12 week treatment course of PTNS were more likely to continue with maintenance PTNS therapy (p=0.005). There were significantly more females (p=0.048) and patients that reported subjective improvement (p<0.001) that continued with maintenance PTNS compared to those that did not. Univariate analysis demonstrated correlation between subjective improvement, female sex, and greater number of completed PTNS sessions with continued maintenance PTNS. Multiple logistic regression only identified sex as a predictor of ongoing maintenance PTNS (OR=13.2; p=0.017).

The present study identified younger age as a significant predictor of progression to further 3rd line OAB treatments after PTNS. Furthermore, female sex was found to be a significant predictor of ongoing maintenance PTNS.