[1] Iowa City VA Hlth Care Syst, Ctr Comprehens Access & Delivery Res & Evaluat CA, Iowa City, IA USA
[2] Univ Iowa, Dept Psychiat, Carver Coll Med, Iowa City, IA 52242 USA
[3] Univ Iowa, Dept Internal Med, Carver Coll Med, Iowa City, IA 52242 USA
[4] Univ Arkansas Med Sci, Inst Psychiat Res, Div Hlth Serv Res, Little Rock, AR 72205 USA
[5] Univ Iowa, Coll Publ Hlth, Dept Epidemiol, Iowa City, IA 52242 USA
[6] Univ Iowa, Carver Coll Med, Dept Neurosurg, Iowa City, IA 52242 USA
[7] Univ Iowa, Carver Coll Med, Dept Surg, Iowa City, IA 52242 USA