1. VA Tennessee Valley Healthcare System , 1310 24th ave S 37212 , USA
2. Department of Biomedical Informatics, Vanderbilt University Medical Center , 2525 West End Avenue, Suite 1475, 37203 , USA
3. Department of Medicine, Vanderbilt University Medical Center , 1161 21st Ave S 37232 , USA
4. Department of Biostatistics, Vanderbilt University Medical Center , 2525 West End Avenue, Sute 1100 37203 , USA
5. Department of Emergency Medicine, Vanderbilt University Medical Center , 2215 Garland Ave 27232 , USA
6. Geriatric Research, Education, and Clinical Center, Tennessee Valley Healthcare System , 1310 24th ave S 37212 , USA
7. Vanderbilt Center for Health Services Research , 1211 Medical Center Drive 37232 , USA
8. Department of Anesthesiology, Vanderbilt University Medical Center , 1211 Medical Center Drive 37232 , USA