[1] Johns Hopkins Univ, Bloomberg Sch Publ Hlth, Dept Epidemiol, Baltimore, MD USA
[2] Johns Hopkins Univ, Sch Med, Div Infect Dis, Baltimore, MD USA
[3] Johns Hopkins Univ, Sch Med, Dept Casemix Informat Management, Baltimore, MD USA
[4] Johns Hopkins Univ, Sch Med, Dept Antibiot Management, Baltimore, MD USA
[5] Johns Hopkins Univ, Sch Med, Dept Hosp Epidemiol & Infect Control, Baltimore, MD USA