1. Department of Family and Community Medicine, Texas Tech University and Lamb Health Care Center, Littlefield, TX 79339, USA
2. Siouxland Medical Educational Foundation and Siouxland Community Health Center, Sioux City, IA 51104, USA
3. College of Sciences and Health Professions, Albany State University, Albany, GA 31705, USA
4. Department of Family Medicine, Michigan State University, East Lansing, MI 48824, USA