Responsiveness, Minimal Detectable Change, and Minimal Clinically Important Difference of the Turkish Version of the 8-item Overactive Bladder Questionnaire

Introduction and Hypothesis: The 8-item Overactive Bladder Questionnaire (OAB-V8) is a readily available instrument for assessing overactive bladder (OAB) symptoms in clinical and research settings. Despite its established validity in Turkish, its psychometric property remains unevaluated. This study aimed to determine the responsiveness, minimal detectable change (MDC), and minimal clinically important difference (MCID) of the Turkish version of the OAB-V8. Methods: This retrospective study consisted of 160 women (age 47.49 ± 12.07 years) with OAB who completed a standardized, guideline-adherent 8-week pelvic floor muscle training. The OAB-V8 was administered pre- and post-training. The responsiveness of the OAB-V8 was assessed using the Wilcoxon signed-rank test, standardized response means (SRMs), and effect sizes (ESs). The MDC was calculated at the 95% confidence level. Receiver operating characteristic (ROC) analysis was used to determine the MCID, maximizing both sensitivity and specificity. Results: The responsiveness of the Turkish version of the OAB-V8 was excellent (ES = 1.57, SRM = 1.56, p < 0.001). The MDC and MCID values were 12.97 and 12.50, respectively. The ROC analysis demonstrated excellent discriminative ability, with an area under the curve of 0.99 (sensitivity 98.0%, specificity 90.0%). Conclusions: The main findings of this study confirm that the OAB-V8 demonstrated excellent responsiveness and discriminative ability, making it an effective tool for assessing symptoms in women with OAB. Clinicians can confidently use the Turkish version of the OAB-V8 scale to not only monitor treatment efficacy but also to determine whether the observed changes are both statistically significant and clinically relevant for the patient.