1. Department of Family Medicine; Oregon Health and Science University; Portland 97239 OR USA
2. Department of Public Health and Preventive Medicine, Division of Biostatistics; Oregon Health and Science University; Portland 97239 OR USA
3. Department of Biobehavioral Health; Pennsylvania State University; University Park 16802 PA USA
4. Division of Sleep Medicine; Harvard Medical School; Boston 02115 MA USA
5. Department of Medicine; Brigham and Women's Hospital; Boston 02115 MA USA
6. Department of Social and Behavioral Sciences; Harvard T.H. Chan School of Public Health; Boston 02115 MA USA
7. Department of Biostatistics; University of Michigan; Ann Arbor 48109 MI USA