Validation of the Croatian Version of the 8-Item Overactive Bladder Questionnaire (OAB-V8).

Objectives: The present study was conducted with the aim to translate, adapt, and validate the 8-item Overactive Bladder Questionnaire (OAB-V8) in Croatia.

Methods: This study included a total of 58 female patients with OAB and 66 healthy women. The translation to Croatian followed standardized procedure. All eligible participants completed OAB-V8 at inclusion and 2 weeks after to assess test-retest reliability. Cronbach α coefficient was calculated to assess internal consistency.

Results: Our study demonstrated high internal consistency for all items at both visits (Cronbach α between 0.799 and 0.847), with stable internal consistency reliability across items during the 2-week period. However, the exception is the item "waking up at night to urinate," which significantly changed during the 2-week period. Intraclass correlation for OAB-V8 items ranged from 0.810 to 1.0, with Spearman correlations greater than 0.9 for all items (P < 0.01). There were strong significant correlations between frequency of urination during daytime and uncomfortable and sudden urge to urinate, and between nocturia and waking up at night. Discriminative validity showed statistically significant score differences between patients and the control group.

Conclusions: The Croatian version of the OAB-V8 was successfully translated, adapted, and validated so the questionnaire is now ready for use as a reliable tool for initial screening and assessing patients with OAB in everyday Croatian clinical practice.