The researchers tested stored blood to determine whether patients had HCV infection, as well as hepatitis caused by the hepatitis A and B viruses. They also collected information on study participants from death registries, interviews with patients and family members, medical records, and autopsy reports. Patients were classified as alcohol abusers if they met at least one of the following conditions: they reported losing friends, family, or a job because of drinking; they admitted to ever having alcoholism; their medical records indicated heavy drinking; or they reported drinking more than 80 grams of alcohol daily.