1. Departments of Medicine and Health Policy and Medical Ethics, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA (S.J.M., K.G.V., D.A.A., L.R.G., L.B.R., L.A.N., L.G.I.).
2. The Corporal Michael J Crescenz VA Medical Center, Philadelphia, PA (S.J.M., K.G.V., D.A.A.).
3. Division of Biostatistics, Department of Population Health, New York University School of Medicine, New York, NY (A.B.T.).