1. Department of Medicine, Baylor College of Medicine, Houston, Texas.
2. Houston Center for Quality of Care and Utilization Studies, Michael E. DeBakey Veterans Affairs Medical Center, Houston, Texas.
3. Department of Family and Community Medicine, Baylor College of Medicine, Houston, Texas.
4. Current affiliation: Hill Country Medical Clinic, Fredericksburg, Texas.
5. Current affiliation: Department of General Internal Medicine, The University of Texas M. D. Anderson Cancer Center, Houston, Texas.
6. Thomas Street Health Center, Harris County Hospital District, Houston, Texas.