[1] Univ Arizona, Mel & Enid Zuckerberg Coll Publ Hlth, Epidemiol & Biostat, 1295 N Martin Ave,Drachman Hall,206H Cubicle, Tucson, AZ 85719 USA
[2] Univ Arizona, Coll Med, Family & Community Med, Tucson, AZ 85719 USA
[3] Univ Arizona, Banner Univ, Div Geriatr Med, Internal Med,Coll Med Phoenix,Med Ctr Phoenix, Tucson, AZ 85719 USA
[4] George Washington Univ, Emergency Med, Washington, DC USA
[5] US Acute Care Solut, Canton, OH USA