Reproducibility study of Overactive Bladder Symptom Score questionnaire and its response to treatment (RESORT) in Korean population with overactive bladder symptoms

The Overactive Bladder Symptom Score (OABSS) is comprised of 4 items with a single total score for quantification of OAB symptoms and has been reported as sensitive to treatment-related changes. The aim of this study was to assess the psychometric properties of the Korean version in patients with OAB symptoms.

Two prospective trials were conducted at two teaching hospitals. The Part I study evaluated the internal consistency and test–retest reliability among 42 enrolled patients, and the Part II trial assessed the construct validity and anticholinergic responsiveness in 50 enrolled patients and 50 controls.

Internal consistency was found acceptable, with Cronbach’s α of 0.73 for total OABSS score. From a 2-week test–retest, Spearman’s rho of each item ranged from 0.53 to 0.82, and the intraclass correlation coefficient of the total score was 0.80, showing the high stability. Acceptable discriminant validity was demonstrated, with substantially different correlations of OABSS scores with an International Prostate Symptom Score-storage and voiding score sum, and significant differences between patients and controls. Convergent validity was acceptable, with moderate correlations between each OABSS item and the corresponding 3-day frequency–volume chart variables. The Korean version was found considerably responsive to symptom changes following 12-week solifenacin treatment, as judged by moderate or large effect sizes, standardized response means, and the Guyatt Responsiveness Index.

With good psychometric properties and responsiveness, the Korean version of the OABSS may offer researchers and clinicians a valid and reliable measure for the assessment of OAB symptoms in the Korean population.