[1] Michael E DeBakey VA Med Ctr, Ctr Innovat Qual Effectiveness & Safety, Houston, TX USA
[2] Michael E DeBakey VA Med Ctr, Patient Care Serv, Houston, TX USA
[3] Baylor Coll Med, Dept Med, Sect Hlth Serv Res, Houston, TX USA
[4] Houston Vet Affairs Med Ctr, Hlth Serv Res & Dev 152, 2002 Holcombe Blvd, Houston, TX 77030 USA