Prevalence of prostatitis-like symptoms in a population based study using the National Institutes of Health chronic prostatitis symptom index

Purpose: The National Institutes of Health (NIH) chronic prostatitis symptom index was used to determine the prevalence of prostatitis-like symptoms among men (age 20 to 74 years) at risk in a community based study. Materials and Methods: The study was a cross-sectional postal survey of men age 20 to 74 years in Lennox and Addington counties, which included a large rural area, I major town and a suburban area with a stable population of men representative of Canadian demographics. The questionnaire collected information on 2 domains of chronic prostatitis identified in the NIH chronic prostatitis symptom index, including pain (location, severity and frequency), voiding function (irritative, obstructive), demographics, quality of life, general health and health seeking behavior. The self-reported pain score was used to identify prostatitis-like symptoms in the most discriminating domain. Based on analysis of the index final validation study comparing patients with prostatitis to normal controls and those with benign prostatic hyperplasia, the 2 questions most specific for prostatitis, including perineal and/or ejaculatory pain/discomfort, and a total pain score (0 to 21) 4 or greater were used to identify men with significant prostatitis-like symptoms. Results: A total of 2,987 eligible men received the survey, and it was completed by 868 (29%). Of the men 84 (9.7%) were identified as having chronic prostatitis-like symptoms (mean NIH chronic prostatitis symptom index pain score 9.1 +/- 0.3). The average age of the prostatitis population was 50 years compared with 52 years for men without prostatitis-like symptoms. Prevalence was 11.5% in men younger than 50 years and 8.5% in men 50 years or older. Of the sampled population 57 (6.6%) men had prostatitis-like symptoms and an index pain score 8 or greater (moderate to severe). The index voiding score (0 to 10) was 4.1 +/- 0.5 in men younger than 50 years compared with 1.5 +/- 0.1 for normal controls, and 4.7 +/- 0.4 in those 50 years or older compared with 1.9 +/- 0.1 for normal controls. Of the prostatitis group 60% sought medical help for their symptoms. Conclusions: In our opinion this community based study using the new prostatitis symptom index confirms that chronic prostatitis-like symptoms are common.