1. Department of Health Policy and Management, School of Rural Public Health, Texas A&M Health Science Center, College Station, Texas.
2. Department of Epidemiology and Biostatistics, School of Rural Public Health, Texas A&M Health Science Center, College Station, Texas.
3. Department of Health Promotion and Community Health Sciences, School of Rural Public Health, Texas A&M Health Science Center, College Station, Texas.
4. Division of Research, Department of Family Medicine, Scott & White Santa Fe, Temple, Texas.