The letter also provided information about HCV transmission, effect on the liver, and effect on general health. In addition, beginning in 2005-2006, serum samples from participants with a positive or indeterminate result for anti-HCV were tested for hepatitis C RNA (HCV-RNA);

starting in 2007, participants with an indeterminate test result for anti-HCV and a positive HCV-RNA also were sent an ROF letter. Because a primary aim of the follow-up survey was to assess what actions participants this website took after becoming aware of their first positive test result, attempts to administer a follow-up telephone questionnaire to all those who were sent an ROF letter began 6 months after examination (approximately 4-5 months after the ROF letter was mailed) to allow participants time to have initiated or implemented actions after notification. Persons ≥18 years of age were interviewed directly; an adult proxy provided information

for participants who were <18 years of age and for individuals unable to answer the questions themselves. The HCV Follow-up Questionnaire (available at: www.cdc.gov/nchs/nhanes/nhanes2003-2004/questexam03_04.htm) was mentioned in the informed consent and also in the ROF letter. Bilingual AP24534 mouse (i.e., English and Spanish) trained interviewers contacted eligible participants by telephone for the interview. Participants who lived in households with no telephones were sent a letter asking them to call a toll-free number to answer a few questions about their hepatitis C results. Participants with communication

or cognitive difficulties that made it impossible to respond to the questionnaire, and for whom a parent or guardian was not available to complete the interview, were excluded. For the main NHANES survey, participants were interviewed in their homes to ascertain demographic characteristics, access to care, and health insurance coverage, using the Computer-Assisted Personal Interviewing (i.e., interviewer-administered) system. Having a usual source of medical care was determined by responses to the question: “Is there a place that medchemexpress you/sampled person usually go/goes when you are/he/she is sick or you/s/he needs advice about your/his/her health? Qualitative determination of anti-HCV in blood serum or plasma was measured using direct solid-phase enzyme immunoassay with an anti-HCV screening enzyme-linked immunosorbent assay (ELISA) (Ortho CD VITROS Anti-HCV Immunodiagnostic System; Ortho Clinical Diagnostics, Raritan, NJ). Positive specimens were repeated in duplicate according to the same procedure. Repeatedly positive specimens were then tested using a confirmatory recombinant immunoblotting assay (RIBA) (Chiron RIBA Processor System, Chiron RIBA HCV 3.0 Strip SIA; Chiron Corporation, Inc., Emeryville, CA), an in vitro qualitative enzyme immunoassay for the detection of anti-HCV in human serum or plasma.