Validation of the Italian version of the Peyronie's Disease Questionnaire (PDQ)

Peyronie's disease (PD) is a connective tissue disorder characterized by the formation of fibrous plaques in the tunica albuginea of the penis which can result in pain, deformity and erectile dysfunction (ED). The Peyronie's Disease Questionnaire (PDQ) assesses the severity of symptoms, including pain, penile curvature and ED, as well as the impact on sexual function, emotional well-being, and overall quality of life of PD patients. Previous studies validated the PDQ in languages other than English and confirmed its test-retest reliability and clinical utility. Despite this, in many countries the unavailability of an adequate PDQ validation in native language hampers its use in clinical practice. In the present non-interventional, observational study we aimed at validating the Italian version of the PDQ (PDQ-I). Between January 2019 and November 2021, 79 PD patients from 6 Italian high-volume centers were administrated the PDQ-I in two separated office visits distanced by a period of 6 months. Intraclass correlation coefficients (ICCs) were used to evaluate the association between the three PDQ scale scores at visit 1 and 2. Paired t-tests were used to evaluate significant score changes between the 2 visits. Cronbach's alpha was used to assess internal consistency reliability. PDQ-I demonstrated an excellent test-retest reliability in the Italian population (ICC 0.78-0.92) as well as a strong internal consistency, with all three scale scores showing a Cronbach's alpha coefficient above 0.70. PDQ-I proved to be a useful tool which allows to reliably evaluate Italian PD patients' quality of life in both everyday andrological practice and clinical research. External validation of our results is pending.