[1] Washington Univ, Brown Sch, Prevent Res Ctr St Louis, Campus Box 1196,One Brookings Dr, St Louis, MO 63130 USA
[2] North Carolina State Univ, Dept Pk Recreat & Tourism Management, Coll Nat Resources, Raleigh, NC USA
[3] Univ Arkansas, Agr Stat Lab, Fayetteville, AR 72701 USA
[4] Med Univ Vienna, Dept Epidemiol, Ctr Publ Hlth, Vienna, Austria
[5] Washington Univ, Sch Med, Dept Surg, Div Publ Hlth Sci, St Louis, MO 63110 USA
[6] Washington Univ, Sch Med, Dept Surg, Alvin J Siteman Canc Ctr, St Louis, MO 63110 USA