The translation and validation of Chinese overactive bladder symptom score for assessing overactive bladder syndrome and response to solifenacin treatment.

Background/purpose: Overactive bladder symptom score (OABSS) was developed by a Japanese urologist and is widely used in Asian countries. The aim of this study was to develop and validate a Chinese OABSS for assessing overactive bladder (OAB) and treatment outcome after solifenacin.

Methods: The Chinese OABSS was developed by linguistic validation of the original version. Its reliability and validity, and correlations with a three-day bladder diary were tested. Patients answered the Chinese OABSS at enrollment and repeated the questionnaire after a non-treatment period of 2 weeks, and at 4 and 12 weeks after solifenacin (5mg/day). Patients also completed a three-day bladder diary and forms including patient perception of bladder condition, International Prostatic Symptom Score and quality of life index at each study visit (for a total of four visits). An analysis was conducted to evaluate the reliability and validity of the Chinese OABSS and the correlations with a three-day bladder diary and a patient perception of bladder condition, respectively.

Results: A total of 60 patients with OAB, including 31 OAB wet and 29 OAB dry, were enrolled. The test-retest reliability of Chinese OABSS was moderate to good with weighted kappa coefficients of 0.515-0.721 for each symptom score and 0.610 for total symptom score. Forty-eight (80%) patients completed the responsiveness study and were followed-up at all time points. Patients' OAB symptoms improved significantly from baseline to 3 months after solifenacin treatment. The changes in OABSS decreased gradually with time within the three months of solifenacin treatment.

Conclusion: The Chinese OABSS has been validated as a reliable instrument for assessing OAB. Solifenacin 5mg once daily improved urgency and other symptoms of OAB including frequency, urge incontinence, OABSS and International Prostatic Symptom Score. The adverse effects were acceptable and became less significant with time in the three months of treatment.