Objectives: To study the prevalence of symptoms of prostatism in the community and the correlation between these symptoms and age, prostate volume, flow rate and residual urine volume.
Subjects and methods: The International Prostate Symptom Score (IPSS) was administered to a community-based population of 502 men aged between 55 and 74 years with no prostate cancer and no history of a prostate operation. Prostate volume parameters, flow rate variables and post-void residual urine volume were measured.
Results: Overall, 6 and 24% of the men were severely and moderately symptomatic, respectively. The results of a detailed questionnaire such as the IPSS (only 12% of the men scored 0) contrast with the men's global perception of their voiding function (82% claimed to have 'no voiding complaints'). A good correlation was found between the total symptom score and the single disease-specific quality of life question that is included in the IPSS (r = 0.74, P = 0.001). There was a weak correlation between the IPSS and total prostate volume (r = 0.19, P < 0.001), and between the IPSS and physiological measures such as peak flow rate (r = -0.18, P < 0.001) and post-void residual urine volume (r = 0.25, P < 0.001). There was a very weak correlation between the IPSS and age (r = 0.09, P = 0.04).
Conclusions: The parameters used to characterize benign prostatic hyperplasia (BPH) should be considered independently because no predictions about the value of a certain parameter can be made by knowing one of the other parameter values. Symptom scores should therefore not be used as a pre-selection criterion in the determination of the prevalence of clinical BPH without taking other measures into account. The interpretation of the parameter values in a clinical setting should take the lack of correlation and the variability of the parameter values into account.