p-pdf-only no pmc-prop-suppress-copyright no pmc-prop-is-real-version no pmc-prop-is-scanned-article no pmc-prop-preprint no pmc-prop-in-epmc yes pmc-license-ref CC BY Introduction In 2006, between 50-70 million adults in the United States had perceived chronic sleep or wakefulness issues, which is an increasing trend, and more than 35% of adults report having insufficient sleep [ 1 ].
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