1. Department of Cardiovascular Medicine, Mayo Clinic, Rochester, MN, USA
2. Division of Pulmonary and Critical Care Medicine, Department of Medicine, Mayo Clinic, Rochester, MN, USA
3. Division of Preventive, Occupational and Aerospace Medicine, Department of Medicine, Mayo Clinic, Rochester, MN, USA
4. Division of Health Science Research, Robert D. and Patricia E. Kern Center for Health Care Delivery, Mayo Clinic, Rochester, MN, USA