The Italian version of the National Institutes of Health Chronic Prostatitis Symptom Index

Objectives: To perform the Italian version of the National Institutes of Health Chronic Prostatitis Symptom Index (NHI-CPSI), and to study its linguistic validity and its correlations with the Visual Analogue Scale for pain (VAS) and the Italian version of International Prostatic Symptom Score (I-PSS) in men with chronic pelvic pain syndrome (CPPS) and healthy controls. Methods: A rigorous double-back translation of the original English NHI-CPSI was performed by a staff composed of 3 professional bilingual experts and 3 urologists. The study population consisted of 160 male CPPS patients and 125 healthy controls, who were asked to self complete the Italian version of the NHI-CPSI together with the VAS and the Italian I-PSS. The discriminatory power, psychometric properties, internal correlations and convergent validity of the questionnaire were tested. Results: Of the 285 enrolled patients, 223 patients (142 with CPPS and 81 healthy patients) were definitively considered for the study. The overall Italian NIH-CPSI scores and each subscale differed significantly (p < 0.001) between the two groups, and so that the index proved a good discriminant validity. High correlations were found between the VAS and the pain domain (0.88) and between I-PSS and void domain (0.94), suggesting a good convergent validity of the Italian version of the NIH-CPSI. The questionnaire proved to have a high internal consistency. Conclusions: The Italian NIH-CPSI is a reliable symptom index that can be self-administrated in about 5 minutes in daily clinical practice for the follow-up of the Italian patients with chronic prostatitis. (c) 2004 Elsevier B.V. All rights reserved.