Introduction: The 33-item Overactive Bladder questionnaire (OAB-q; 1-week recall version) has been psychometrically validated in middle-aged, generally healthy patients with overactive bladder. The present analysis was conducted to determine the psychometric validity of the OAB-q in medically complex elderly patients.
Methods: OAB-q structure was evaluated using a second-order confirmatory factor analysis (CFA) model with five domains and one aggregated domain, using pooled data from two clinical trials (786 observations) for urgency urinary incontinence (UUI). Psychometric validity was evaluated with CFA, Cronbach coefficient α (CCA) for reliability, Spearman correlations for convergent validity, differences in OAB-q scores in relation to UUI severity and Patient Perception of Bladder Condition (PPBC) scores for known-groups validity, and effect size (ES) of differences in mean scores of OAB-q domains over time for treatment responsiveness.
Results: Participants were predominantly female (82.2%) and white (85.9%); mean age was 75.0 years. The second-order CFA was confirmed with a Bentler's comparative fit index of 0.90, t values for path coefficients of >1.96, and standardized path coefficients of >0.40. OAB-q domains demonstrated good internal consistency (CCA >0.7). Convergent validity was supported by moderate correlations (0.4-0.7) between OAB-q domain and PPBC scores. Significant differences in OAB-q domain scores between groups with different symptom severity established known-groups validity. Significant changes in mean OAB-q scores from baseline to week 12 with moderate-to-large ES (0.50-0.80) demonstrated treatment responsiveness.
Conclusions: The OAB-q demonstrates reliability, concurrent and discriminant validity, and responsiveness to treatment. The evidence shows that the OAB-q is psychometrically sound for use in medically complex elderly patients with overactive bladder.
Keywords: Medically complex elderly; Overactive bladder; Overactive bladder questionnaire; Patient-reported outcomes; Psychometric validation.