1. Western University of Health Sciences, Pomona, California (I.T.T., A.S., T.R.)
2. Western University of Health Sciences, Pomona, and VA Greater Los Angeles Healthcare System, Los Angeles, California (J.M.)
3. VA Greater Los Angeles Healthcare System and David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, California (F.V.M., J.K.H.)
4. Western University of Health Sciences, Pomona, California; VA Greater Los Angeles Healthcare System, Los Angeles, California; ICES, Toronto, Canada; and Institute of Health Policy, Management and Evaluation, University of Toronto, Toronto, Ontario, Canada (C.A.J.).