Objectives: The objective of this study was to validate the Italian version of the Urogenital Distress Inventory (UDI) in a sample of women with lower urinary tract symptoms (LUTS).
Methods: The linguistic validation of the questionnaire was performed through a multistep process: backward and forward translations coordinated by clinical investigators, followed by a pretest. The final version was administered to a larger sample of female patients, aged 18 years or older who had been having LUTS for at least 3 months, numbering 53 subjects. To evaluate test-retest reliability, patients were re-rated after 1 week. To test the questionnaire's capacity to discriminate women with or without LUTS (cases and controls, respectively), a sample of 53 healthy women was enrolled. A 72-h voiding diary was used as a gold standard and compared with the UDI.
Results: The correlation coefficient between ratings was >or=0.80, and the discriminant power between cases and controls was confirmed. The UDI showed good internal consistency for all domains, except irritative symptoms (total score's Cronbach alpha=0.86). Factor analytic structure revealed urinary incontinence to be opposite to the other urologic symptoms, with bed wetting being loaded separately. The average daily number of urgent micturitions was higher in patients who reported they "experience a strong feeling of urgency to empty bladder" in the UDI than those ones who did not (p<0.01).
Conclusions: The Italian version of the UDI is a valid and robust instrument, which can now be used reliably in daily practice and clinical research.