Defining response and non-response to treatment in patients with overactive bladder: a systematic review

Abstract

Objective: There is currently a lack of formal guidance for assessing treatment response and non-response in patients with overactive bladder (OAB). Such guidance would be useful for both clinical practice and the design of clinical trials. Our purpose was to review and assess definitions of treatment response and non-response used in patients with OAB.

Methods: We conducted a systematic review of articles published between January 1, 2005 and August 8, 2013 using PubMed. Search terms included (overactive bladder) AND ('treatment response' OR responder OR success OR satisfied OR goal OR refractory OR nonresponder OR fail OR persistent OR dissatisfied). Limits were 'humans' and 'English'. Studies conducted in subjects with neurogenic detrusor overactivity, conditions other than OAB, or OAB symptoms following lower urinary tract/pelvic surgery were excluded; case reports and letters were also excluded.

Results: The literature search returned 423 articles, of which 75 met the inclusion criteria and defined a specific threshold by which treatment response or non-response was determined for patients receiving behavioral therapy and/or treatment with an antimuscarinic, β3-agonist, botulinum toxin, or neural stimulation. One published abstract from congress proceedings and three additional articles that were not identified by the search were included; thus, a total of 79 records were included. A wide variety of symptom-based definitions and patient-reported outcomes (PROs) were used. Symptom-based definitions frequently used a threshold of 50-100% improvement in general or specific symptoms; urgency urinary incontinence (UUI) was often used in studies with incontinent patients. Definitions based on PROs frequently used measures of satisfaction, general improvement, or goal achievement. Studies of patients with refractory OAB often referred to a failure to respond to ≥1 other therapy, or to poor efficacy or unacceptable tolerability, without further specification. Limitations of this review are that only English language articles were included and that only the PubMed database was used for the literature search.

Conclusions: There is considerable heterogeneity in the definitions of treatment response and non-response in trials of patients with OAB; some standardization would be beneficial. However, there is also heterogeneity among patients of what constitutes treatment success or failure, and conceptualizations of treatment response and non-response in both clinical trials and clinical practice must take patient characteristics into account. For patients with UUI, it is recommended that the criteria for treatment response include this symptom, as measured by change in the absolute number of UUI episodes or achievement of continence, given its impact on patients' lives and associated bother. PROs provide important information that confirm symptom-based measures by demonstrating that observed changes in symptoms are meaningful to the patient. In clinical practice, measures of treatment satisfaction and goal achievement can be highly useful.