1 1 Division of Pharmacoepidemiology, Department of Health Policy, Vanderbilt University Medical Center, Nashville, Tennessee.
2 2 Veterans Health Administration-Tennessee Valley Healthcare System Geriatric Research Education Clinical Center, Health Services Research and Development Center, Nashville, Tennessee.
3 3 Division of Pulmonary, Allergy, and Critical Care Medicine, Department of Medicine and Department of Epidemiology, Columbia University Medical Center, New York, New York; and.
4 4 Division of Infectious Diseases, Department of Medicine and Department of Health Policy, Vanderbilt University Medical Center, Nashville, Tennessee.