Overactive bladder (OAB) symptoms of urinary urgency/frequency/incontinence have many influences including age-related degeneration, neural/cerebral pathology, hormonal changes, infection, and anatomical alterations (eg, urethral obstruction). OAB’s multifactorial nature precludes a single treatment cure; in fact, one could argue there is no cure. While treatments exist, unfortunately, they are not always successful. In general, the achievable management goal is symptom improvement. What degree of improvement justifies continued treatment? How durable is the success? These crucial issues need to be considered when counseling patients about various OAB treatment options.

Initial management of OAB is conservative and involves education, behavior modification, and pelvic floor rehabilitation. Compliance and, therefore, success with first-line treatments is limited. As a result, many individuals move on to second-line therapy (anticholinergic and beta-adrenergic medications). While many achieve some degree of symptomatic improvement with these measures, cost, side effects, and inadequate efficacy lead to poor patient satisfaction.¹ Third-line OAB treatment options include neuromodulation (sacral neuromodulation [SNM], posterior tibial nerve stimulation [PTNS]) and botulinum toxin (BTX) injections. Historically, a >50% symptomatic improvement has been required to justify continuation of third-line therapies. To our knowledge, the rationale of choosing a 50% threshold is unknown. It seems somewhat arbitrary and is indicative of our failure to truly “cure” the problem.²

Over time, reductions in third-line OAB treatment efficacy may lead to patient dissatisfaction, progression to alternate forms of therapy, and additional costs. Ideally one would be able to identify patients at risk for long-term failure in order to avoid unnecessary costs and frustration. Five-year loss of efficacy was reported in about one-third of patients managed with SNM.³ Long-term loss of efficacy has also been reported for both PTNS and BTX injections.^4-7

Intuitively, one would think a patient with an initially higher degree of symptomatic improvement with third-line OAB therapy might fare better in the long term compared to one with a lesser degree of improvement. While this has not been formally studied in a prospective trial, there are suggestions it is true. Foster et al observed that the degree of pad weight reduction and pad usage during SNM was predictive of a patient’s willingness to “do it all over again” (P = .005) and long-term satisfaction (P = .005) with satisfied patients experiencing an 85% reduction in pad weights, whereas dissatisfied patients only experienced a 61% reduction.⁸ In a recent study, we reported significantly more patients continued to benefit from SNM over time (mean followup of 46 months) if they experienced a >75% overall improvement compared to those only experiencing a 50%-75% improvement during the initial test phase (68% vs 44%); a >75% improvement in symptoms during testing was a predictor of long-term success.⁹

This begs the question: is a 50% improvement in OAB symptoms good enough? If a greater threshold is used to determine treatment efficacy justifying continued treatment, then fewer patients will qualify and receive this treatment. Based on our results, if the improvement threshold to justify SNM implant were increased to >75%, then 44% of our implanted patients who were still benefiting from the stimulation would not have been eligible for the implant. Considering that patients undergoing third-line OAB therapies have failed the more conservative therapies, one could argue that any improvement is better than nothing at all. But one needs to be circumspect given that there can be significant cost associated with the treatment, and the treatment could require frequent visits that might be a burden to the patient (eg, PTNS) and even carry some small risks (eg, device infection with SNM, urinary retention, and UTI with BTX injections). While no study has conclusively shown one third-line OAB option to be superior to the another, there may be cost differences between them. In fact, a recent treatment cost analysis using the data from the ROSETTA trial comparing SNM to BTX injections (granted 200 units of BTX was used rather than the standard 100 units) showed that SNM, despite similar efficacy with respect to urge incontinence improvement, had significantly higher costs at 2 and 5 years.¹⁰ Given that options beyond third-line OAB therapies may involve major surgery with significant associated risks both in the short and long term (eg, bladder augmentation, urinary diversion), the use of a 50% improvement threshold to determine eligibility for ongoing treatment for the time being is probably reasonable. However, we need to be honest with patients and set realistic expectations regarding their prognosis with these treatments.