[1] Univ Maryland, Sch Publ Hlth, Dept Epidemiol & Biostat, 4200 Valley Dr,Suite 2234, College Pk, MD 20742 USA
[2] Harvard T H Chan Sch Publ Hlth, Dept Social & Behav Sci, Boston, MA USA
[3] US Census Bur, Ctr Econ Studies, Mortal Res Grp, Suitland, MA USA
[4] Univ Maryland, Sch Publ Hlth, Dept Behav & Community Hlth, College Pk, MD USA