Patterns of hepatitis C prevalence and seroconversion in hemodialysis units from three continents: The DOPPS. Hepatitis C virus (HCV) remains a problem within hemodialysis units. This study measures HCV prevalence and seroconversion rates across seven countries and investigates associations with facility-level practice patterns. The study sample was from the Dialysis Outcomes and Practice Patterns Study (DOPPS), a prospective, observational study of adult hemodialysis patients randomly selected from 308 representative dialysis facilities in France, Germany, Italy, Japan, Spain, the United Kingdom, and the United States. Logistic regression was used to model odds of HCV prevalence, and Cox regression was used to model time from study entry to HCV seroconversion. Mean HCV facility prevalence was 13.5% and varied among countries from 2.6% to 22.9%. Increased HCV prevalence was associated with longer time on dialysis, male gender, black race, diabetes, hepatitis B (HBV) infection, prior renal transplant, and alcohol or substance abuse in the previous 12months. Approximately half of the facilities (55.6%) had no seroconversions during the study period. HCV seroconversion was associated with longer time on dialysis, human immunodeficiency virus/acquired immunodeficiency syndrome (HIV/AIDS), HBV infection, and recurrent cellulitis or gangrene. An increase in highly trained staff was associated with lower HCV prevalence (OR = 0.93 per 10% increase, P = 0.003) and risk of seroconversion (RR = 0.92, P = 0.07). Seroconversion was associated with an increase in facility HCV prevalence (RR = 1.36, P < 0.0001), but not with isolation of HCV-infected patients (RR = 1.01, P = 0.99). There are differences in HCV prevalence and rate of seroconversion at the country and the hemodialysis facility level. The observed variation suggests opportunities for improved HCV outcomes.