The epidemiology of acute urinary retention in benign prostatic hyperplasia.

One of the most important events in the natural history of BPH is acute urinary retention (AUR). Better estimates of AUR incidence are now available from both population-based studies and placebo control groups (patients diagnosed with BPH). Several strong risk factors for AUR have been identified by analytical epidemiology, the most important being serum PSA levels. When counseling patients with BPH who are considering watchful waiting, clinicians should also take into account prostate volume, maximum flow rate, and symptom severity.