Study subject identification flow sheet. Anti-HBc, hepatitis B core antibody; anti-HBs, hepatitis B surface antibody; HBsAg, hepatitis B surface antigen; HBV, hepatitis B virus; WIHS, Women’s Interagency HIV Study. *Assays used for hepatitis serological analysis at baseline were the Abbott Ausab EIA for anti-HBs, the Abbott Corzyme EIA for anti-HBc, and the Abbott Auszyme Microparticle EIA for HBsAg (Abbott Laboratories); anti-HBs was measured on reposited serum by use of Vitros ECi (Ortho Diagnostics).