After developing validated case definitions to identify IC/BPS or CP/CPPS in the RAND Interstitial Cystitis Epidemiology study, Anne M. Suskind, M.D., of the University of Michigan in Ann Arbor, and colleagues used population-based methods to screen 6,072 households by telephone for men with symptoms of IC/BPP or CP/CPPS. A total of 149 men met the inclusion criteria and completed the telephone survey.The researchers found that the weighted prevalence of IC/BPS was estimated at 4.2 percent for a high-sensitivity definition and 1.9 percent for a high-specificity definition. The weighted prevalence of CP/CPPS was estimated at 1.8 percent. These values would equate to 1,986,972 men with CP/CPPS in the United States and 2,107,727 men with the high-specificity definition of IC/BPS. The estimated overlap between high specificity IC/BPS and CP/CPPS was 17 percent.