The EPIC study was the first large-scale, multinational, population-based, cross-sectional survey to estimate the prevalence of lower urinary tract symptoms (LUTS) using current (2002) International Continence Society (ICS) definitions, with a focus on LUTS subtypes, overactive bladder (OAB), and urinary incontinence (UI). This study was conducted between April and December 2005 using randomly selected men and women >= 18 yr of age living in Canada, Germany, Italy, Sweden, and the United Kingdom. The results of the EPIC study are fairly consistent with the literature, showing that LUTS are highly prevalent; 64.3% of the 19,165 respondents reported experiencing at least one LUTS. Storage LUTS were considerably more prevalent than were voiding and post-micturition LUTS in both men and women. The prevalence of OAB was comparable in men (10.8%) and women (12.8%) and increased with age in both sexes. Nocturia was the most prevalent symptom in both men (48.6%) and women (54.5%). UI was more prevalent among women (13.1%) than men (5.4%). Among women, stress UI and other UI were the most prevalent types of UI; among men, other UI and urgency UI were most prevalent. Rates of physician-diagnosed depression were significantly higher in respondents with OAB, with or without UI, than in respondents without OAB. Further analyses of EPIC data will be available soon and should yield information about OAB regarding bother and impact on quality of life; risk factors and comorbidities; coping and health care-seeking behaviours; and impact on sexuality, mental health, and work productivity. (c) 2006 European Association of Urology. Published by Elsevier B.V. All rights reserved.