1. Johns Hopkins University, School of Medicine, Baltimore, MD
2. University of Nebraska Medical Center, Omaha, NE
3. William S. Middleton Memorial Veterans Hospital, Madison, WI
4. John D. Dingell VA Medical Center and Wayne State University, Detroit, MI
5. University of Pittsburgh, Pittsburgh, PA
6. Mayo Clinic Florida, Transplant Center, Jacksonville, FL
7. Mayo Clinic, Rochester, MN
8. Department of Medicine, Wayne State University School of Medicine, Detroit, MI
9. Sleep Disorders Center, University of California, San Francisco, San Francisco CA
10. American Academy of Sleep Medicine, Darien, IL