Journal of Clinical Sleep Medicine is dedicated to advancing the science of clinical sleep medicine. In order to provide subscribers with access to new scientific developments as early as possible, accepted papers are posted prior to their final publication in an issue. These papers are posted as received-without copyediting or formatting by the publisher. In some instances, substantial changes are made during the copyediting and formatting processes; therefore, the final version of the paper may differ significantly from this version. Unless indicated otherwise, all papers are copyright of the American Academy of Sleep Medicine. No paper in whole or in part may be used in any form without written permission from the American Academy of Sleep Medicine.