Table 2. Self-reported sleep characteristics.

Variable	Baseline (%) (N = 93,668)
Insomnia*
Yes	28,546 (31.2)
No	63,082 (68.9)
Sleep Duration
5 h or less	7,738 (8.3)
6 h	25,076 (26.9)
7 – 8 h	56,060 (60.2)
9 h or more	4,300 (4.6)
Sleep Disordered Breathing (SDB) Score**
High risk	18,117 (19.4)
Low risk	75,499 (80.7)
Comorbid insomnia and SDB score
High risk	7,099 (7.8)
Low risk	84,529 (92.3)

^*Insomnia is defined as a score of 9 or greater on the WHI Insomnia Rating Scale (Levine DW et al. Reliability and validity of the Women's Health Initiative Insomnia Rating Scale. Psychol Assess 2003; 15(2):137-48)

^**Sleep disordered breathing (SDB) score was calculated utilizing risk factors for sleep apnea adapted from the Berlin Questionnaire. The scores ranged from 0 to 3 points and scores ≥2 were considered high risk for SBD and <2 low risk (Rissling MB, Gray KE, Ulmer C, et al. Sleep Disturbance, Diabetes, and Cardiovascular Disease in Post-Menopausal Veteran Women. Gerontologist. 2016.56(Suppl 1):S54-66.)