1. Department of Epidemiology, College of Public Health University of Iowa Iowa City Iowa USA
2. Iowa Institute of Oral Health Research University of Iowa Iowa City Iowa USA
3. College of Pharmacy University of Iowa Iowa City Iowa USA
4. University of Iowa Hospitals and Clinics University of Iowa Iowa City Iowa USA
5. Center for Access and Delivery Research and Evaluation Iowa City VA Health Care System Iowa City Iowa USA
6. Department of Oral Pathology, Radiology and Medicine, College of Dentistry University of Iowa Iowa City Iowa USA