Aims: Valid and reliable questionnaires must be used to accurately assess patients' satisfaction with overactive bladder (OAB) treatment. This study evaluated the reliability and validity of the OAB Satisfaction with Treatment Questionnaire (OAB-SAT-q).
Methods: This was a secondary analysis of clinical study data of patients randomized to darifenacin or darifenacin plus Behavioral Modification Program. Patients completed the Overactive Bladder Questionnaire (OAB-q) and a 3-day bladder diary at Baseline and Week 12 and the OAB-SAT-q at Week 12. Internal consistency reliability was assessed by Cronbach's alpha. Concurrent validity was assessed through correlations with OAB-q change scores and adverse events (AEs). Discriminant validity was assessed among subgroups using general linear models.
Results: Analyses utilized a per-protocol population (completion of OAB-q at Baseline and OAB-q and OAB-SAT-q at Week 12) (n = 375). Exploratory factor analysis of the OAB-SAT-q revealed three 3-item subscales (Satisfaction, Side Effects, Endorsement) and two single items (Convenience, Preference). Cronbach's alphas = 0.84-0.95. Subscale-to-subscale correlations = 0.10-0.67 (all P < 0.01 except Side Effects and Convenience). The Side Effects subscale significantly correlated with number of treatment-related AEs (r = 0.27; P < 0.01) and discriminated between patients with/without dry mouth and patients with/without constipation. The Satisfaction and Endorsement subscales discriminated between patients who worsened or had no change in micturition frequency and urinary urgency and patients who had a reduction of >3 episodes (all P < 0.001). The OAB-SAT-q does not appear to discriminate by incontinence episodes.
Conclusion: The OAB-SAT-q demonstrated good psychometric properties in this initial evaluation-including internal consistency reliability and concurrent and discriminant validity-and appears to be a useful assessment of OAB treatment satisfaction. Neurourol. Urodynam. 28:416-422, 2009. (c) 2008 Wiley-Liss, Inc.