1. Division of Pulmonary, Allergy, Critical Care, and Sleep Medicine, and
2. Division of Biostatistics, University of Minnesota, Minneapolis, Minnesota;
3. Cardiology Section, and
4. Lundquist Institute for Biomedical Innovation at Harbor–University of California Los Angeles Medical Center, Torrance, California; and
5. Lung Health Center, University of Alabama at Birmingham, Birmingham, Alabama
6. Pulmonary Section, Minneapolis Veterans Affairs Health Care System, Minneapolis, Minnesota;