Two-year experience with the german-translated version of the NIH-CPSI in patients with CP/CPPS

To examine, after psychometric evaluation and validation of the translated National Institutes of Health Chronic Prostatitis Symptom Index (NIH-CPSI), the practical value of this questionnaire in a routine diagnostic prostatitis setup for patients with chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS). The NIH-CPSI is a well-accepted tool for the symptomatic evaluation of patients with CP/CPPS. The recently translated German version has not yet been validated in detail.

A total of 137 consecutive patients attending a prostatitis outpatient department were classified according to the internationally accepted NIH consensus classification into CP/CPPS NIH type IIIA (n = 53; mean age 43.2 years) and IIIB (n = 84; mean age 43.4 years). For psychometric analysis, the overall type III group was evaluated for reliability and validity of the German NIH-CPSI. The psychometric properties of the translated NIH-CPSI were compared with those of the original English version. In addition, the total scores of all men and separately for CP/CPPS NIH types IIIA and IIIB were evaluated.

The German NIH-CPSI was reliable, with an alpha coefficient for the overall index and its subscales of between 0.60 and 0.74. However, the internal consistency of the pain subdomain was lower in our translated version (alpha 0.60) compared with the original English version (alpha 0.86). In this cohort, men with NIH type IIIB CP/CPPS were significantly (P = 0.03) more symptomatic in the total index compared with men with NIH type IIIA CP/CPPS.

The German version of the NIH-CPSI has a relatively high reliability and face and construct validity overall. A validated translated NIH-CPSI is suggested as a standardized tool to quantify chronic pelvic pain symptoms for different countries and languages.