[1] Henry Ford Hlth Syst, Dept Publ Hlth Sci, Detroit, MI USA
[2] Henry Ford Hlth Syst, Div Gastroenterol Hepatol, Detroit, MI USA
[3] Henry Ford Hlth Syst, Ctr Hlth Policy & Hlth Serv Res, Detroit, MI USA
[4] Ctr Dis Control, Div Viral Hepatitis, Atlanta, GA 30333 USA
[5] Kaiser Permanente, Ctr Hlth Res Hawaii, Honolulu, HI USA
[6] Geisinger Hlth Syst, Geisinger Ctr Hlth Res, Danville, PA USA
[7] Kaiser Permanente, Ctr Hlth Res NW, Portland, OR USA