1. From the Outcomes Research and Assessment Group, Duke Clinical Research Institute (J.G.J., E.D.P., C.L.N., J.A.S., E.R.D., L.H.M., D.B.M.), the Department of Medicine (J.G.J., E.D.P., C.L.N., J.A.S., D.B.M.), and the Department of Surgery (L.H.M.), Duke University Medical Center, Durham, NC.