[1] Washington Univ, Sch Med St Louis, Dept Med, Div Palliat Med, 4590 Childrens Pl, St Louis, MO 63110 USA
[2] Univ Penn, Sch Nursing, Dept Biobehav Hlth Sci, Philadelphia, PA 19104 USA
[3] Univ Penn, Perelman Sch Med, Dept Biostat Epidemiol & Informat, Philadelphia, PA 19104 USA
[4] Washington Univ, Brown Sch, St Louis, MO 63110 USA
[5] Univ Missouri, Sch Med, Dept Family & Community Med, Columbia, MO USA
[6] Barnes Jewish Coll, Golfarb Sch Nursing, St Louis, MO USA