National Institutes of Health Chronic Prostatitis Symptom Index for Japanese men

Objectives. To establish a Japanese version of the National Institutes of Health Chronic Prostatitis Symptom Index (NIH-CPSI) and to determine its validity and applicability in patients with chronic prostatitis, comparing the results with those from patients with benign prostatic hyperplasia (BPH) and normal men. Methods. The study included 103 patients with chronic prostatitis, 60 with BPH, and 87 normal men who agreed to respond to a self-administered questionnaire of the Japanese version of the NIH-CPSI (JPN-NIH-CPSI). Testing-retesting was done to confirm the reliability of the index in 23 patients with chronic prostatitis, with a 2-week interval between tests. Results. Pain or discomfort was more prominent in the prostatitis group than in the BPH and normal groups. Overall, quality of life in the prostatitis group was impaired more severely than that in the other two groups. The scores of three domains (pain, urinary symptoms, and quality-of-life impact) in the prostatitis group were clearly higher than those in the BPH and normal groups, except for those of urinary symptoms in the BPH group. The test-retest analysis showed good reliability and internal consistency for the JPN-NIH-CPSI, with a Cronbach's alpha coefficient of more than 0.8. Conclusions. The JPN-NIH-CPSI can be reliably used for evaluation of Japanese patients with prostatitis, as is the NIH-CPSI for English-speaking men. (C) 2002, Elsevier Science Inc.