RT Journal T1 BEijing, china JF Archives of Internal Medicine JO Archives of Internal Medicine YR 2011 FD October 24 VO 171 IS 19 SP 1774 OP 1774 DO 10.1001/archinternmed.2011.491 UL http://dx.doi.org/10.1001/archinternmed.2011.491 AB Grahic Jump LocationBeijing, China.