[1] Johns Hopkins Univ, Sch Med, Div Gen Internal Med, Baltimore, MD USA
[2] Johns Hopkins Univ, Welch Ctr Prevent Epidemiol & Clin Res, Baltimore, MD USA
[3] Johns Hopkins Bloomberg Sch Publ Hlth, Dept Epidemiol, Baltimore, MD USA
[4] Johns Hopkins Bloomberg Sch Publ Hlth, Dept Hlth Policy & Management, Baltimore, MD 21205 USA
[5] Towson Univ, Dept Kinesiol, Baltimore, MD USA
[6] Johns Hopkins Univ, Sch Med, Dept Psychiat & Behav Sci, Baltimore, MD 21205 USA
[7] Johns Hopkins Bloomberg Sch Publ Hlth, Dept Biostat, Baltimore, MD USA
[8] Johns Hopkins Carey Business Sch, Baltimore, MD USA