1 Department of Internal Medicine, Vanderbilt University Medical Center, 1161 21st Avenue South, D-3100 Medical Center North, Nashville, TN, USA. kevin.g.buell@vumc.org.
2 Division of Allergy, Pulmonary, and Critical Care Medicine, Vanderbilt University Medical Center, Nashville, TN, USA.
3 Department of Biostatistics, Vanderbilt University Medical Center, Nashville, TN, USA.
4 Department of Anesthesiology, Vanderbilt University Medical Center, Nashville, TN, USA.
5 Department of Biomedical Informatics, Vanderbilt University Medical Center, Nashville, TN, USA.
6 Department of Emergency Medicine, Vanderbilt University Medical Center, Nashville, TN, USA.