Reevaluating predictive factors for treatment success in therapy with OnabotulinumtoxinA for iOAB in a real-world study.

backgroundOnabotulinumtoxinA is an established third-line therapy for idiopathic overactive bladder (iOAB), with efficacy demonstrated in randomized trials and real-world studies. Despite the growing body of literature, predictors of treatment response remain insufficiently defined, with heterogeneous endpoints and definitions across studies. We performed a retrospective analysis to reevaluate prior identified predictors of treatment success using both patient-reported and objective outcomes.

methodsWe included consecutive patients receiving a first intradetrusor injection of 100AE onabotulinumtoxinA for iOAB between January 2018 and April 2026. All patients had prior treatment with at least two anticholinergics and completed a 3-day bladder diary. Urodynamic studies were performed in all men and selectively in women. Injections were administered at 20 detrusor sites sparing the trigone. Outcome was treatment success defined by the Treatment Benefit Scale (TBS; success= 1-2), the definition by Abrar (≥ 50% improvement in urgency and urgency urinary incontinence), or a reduction by 11 points in the Urogenital Distress Inventory (UDI-6). Duration of effect was defined as time to patient-requested reinjection. Univariate logistic regression identified predictors of treatment success and duration (> 12 months, <6 months). A p value < 0.05 was considered statistically significant.

resultsOf 180 treated patients, 175 were included (74.9% female; median age 73 years [IQR 61-78]). Overall, 71.4% achieved success by TBS, 74.3% by Abrar criteria, and 70.3% by UDI-6. No significance differences between the methods were noted (p=0.21). Complete continence was newly achieved in 37.2%. Symptom relief lasted <6 months in 28%, 6-12 months in 45.1%, and >12 months in 26.9%. No major complications occurred but 44.8% developed a urinary tract infection within 3 months after injection. Active smoking (p=0.016) post-OP UTI (p=0.003) and a diabetes mellitus (p=0.005) were negative predictors of treatment success. Female sex (p=0.09) showed a non-significant trend toward treatment success. In multivariate analysis, no variable achieved statistical significance. Age, urodynamic findings, and baseline symptom severity were not predictive. Longer duration (> 12 months) was associated with TBS success (p<0.001), absence of frailty (p=0.01), and newly achieved complete continence (p=0.029). Short duration (< 6 months) was associated with failure to achieve continence (p<0.001) and UTI post-OP (p=0.001). Active smoking (p=0.059) and absence of detrusor overactivity in urodynamic studies (p=0.096) showed trends for short duration.

conclusionOnabotulinumtoxinA is a safe and highly effective treatment option for patients with iOAB and therefore can be offered to all patients. Treatment success is associated with smoking status and metabolism, whereas age and underlying diagnosis do not appear predictive. Postoperative urinary tract infections may adversely affect outcomes and should be minimized. These findings may improve patient counseling and expectation management.