All | Sleep duration* | Time to fall asleep | Frequent night awakenings† | Napping frequency | |||||
Recommended (7–9 hours) | Short (<7 hours) | ≤30 min | >30 min | No | Yes | <3 times/ week | ≥3 times/ week | ||
Sample size, N (%) | 39 071 | 27 880 (72) | 10 835 (28) | 32 566 (83) | 6505 (17) | 34 025 (87) | 5046 (13) | 35 390 (91) | 3681 (9) |
Sociodemographic characteristics | |||||||||
Age, years | 54.8±8.8 | 54.9±9.0 | 54.6±8.5 | 54.8±8.8 | 55.2±8.8 | 54.7±8.9 | 56.0±8.4 | 54.6±8.7 | 57.5±9.5 |
Race/ethnicity | |||||||||
White | 87 | 91 | 79 | 88 | 79 | 87 | 88 | 88 | 83 |
Black | 8 | 5 | 15 | 7 | 13 | 8 | 7 | 8 | 11 |
Hispanic/Latina | 5 | 4 | 6 | 4 | 8 | 5 | 5 | 5 | 6 |
Educational attainment | |||||||||
<HS | 1 | 1 | 1 | 1 | 2 | 1 | 2 | 1 | 2 |
HS/GED | 13 | 13 | 15 | 13 | 17 | 13 | 16 | 13 | 15 |
Some college | 33 | 32 | 35 | 32 | 38 | 32 | 36 | 32 | 35 |
≥Bachelor's | 53 | 55 | 49 | 55 | 43 | 54 | 46 | 54 | 48 |
Marital status | |||||||||
Married or living as married | 76 | 79 | 70 | 77 | 71 | 76 | 76 | 77 | 71 |
Single/never married | 5 | 5 | 7 | 5 | 7 | 6 | 5 | 5 | 6 |
Widowed/separated/ divorced | 19 | 17 | 23 | 18 | 22 | 18 | 19 | 18 | 23 |
Currently working shift/irregular hours, yes | 15 | 15 | 16 | 15 | 15 | 15 | 15 | 15 | 14 |
Total years worked shifts | |||||||||
None | 62 | 62 | 62 | 62 | 62 | 62 | 61 | 62 | 63 |
1–2 | 3 | 3 | 3 | 3 | 3 | 3 | 4 | 3 | 3 |
3–4 | 8 | 9 | 8 | 9 | 8 | 8 | 8 | 9 | 7 |
>4 | 26 | 26 | 27 | 26 | 26 | 26 | 27 | 26 | 27 |
Sleep characteristics | |||||||||
Cumulative sleep score‡ | |||||||||
0 | 53 | 73 | 0 | 63 | 0 | 60 | 0 | 58 | 0 |
1 | 32 | 23 | 54 | 30 | 40 | 31 | 40 | 30 | 53 |
2–4 | 16 | 4 | 46 | 7 | 60 | 9 | 60 | 12 | 47 |
Recent sleep medication use, yes§ | 11 | 10 | 12 | 9 | 19 | 10 | 15 | 10 | 13 |
Health behaviors | |||||||||
Alcohol consumption status | |||||||||
Current | 83 | 84 | 81 | 84 | 79 | 84 | 81 | 84 | 76 |
Past | 13 | 13 | 15 | 13 | 16 | 13 | 15 | 13 | 19 |
Never | 3 | 3 | 4 | 3 | 4 | 3 | 4 | 3 | 5 |
Smoking status | |||||||||
Current | 8 | 7 | 10 | 7 | 11 | 8 | 8 | 7 | 10 |
Past | 35 | 35 | 33 | 35 | 33 | 34 | 38 | 35 | 33 |
Never | 57 | 58 | 57 | 58 | 56 | 58 | 54 | 57 | 57 |
Diet (daily glycemic load) | 84.9±39.1 | 84.0±37.3 | 87.0±43.0 | 84.2±37.6 | 88.1±45.6 | 84.6±38.5 | 86.9±42.6 | 83.9±38.2 | 94.4±45.1 |
Physical activity | 51.6±31.4 | 51.6±31.0 | 51.6±32.4 | 51.7±31.3 | 50.8±31.8 | 51.5±31.3 | 51.6±31.7 | 51.8±31.3 | 49.5±31.6 |
(Metabolic equivalent of task hours) | |||||||||
Clinical characteristics | |||||||||
Mean waist-to-hip ratio | 0.80±0.08 | 0.80±0.08 | 0.81±0.07 | 0.80±0.08 | 0.81±0.07 | 0.80±0.08 | 0.81±0.07 | 0.80±0.08 | 0.81±0.07 |
Waist circumference (cm) over NHLBI guidelines (yes) | 36 | 34 | 41 | 35 | 43 | 36 | 41 | 35 | 46 |
Mean BMI (kg/m2) | 27.2±5.8 | 26.9±5.6 | 28.0±6.3 | 27.0±5.8 | 28.0±6.0 | 27.1±5.8 | 27.7±6.2 | 27.1±5.8 | 28.4±6.4 |
Menopause, yes | 62 | 62 | 63 | 61 | 67 | 61 | 71 | 61 | 71 |
Hypertension, yes | 37 | 36 | 41 | 36 | 42 | 37 | 41 | 36 | 46 |
Clinical depression, yes | 19 | 19 | 19 | 18 | 27 | 19 | 24 | 19 | 27 |
Waist circumference>88 cm for women was defined as exceeding guidelines per the National Heart, Lung and Blood Institute (NHLBI).
The following variables had missing data: diet (daily glycemic load), n=843 (2%). All other variables with missing values were <1% of the total sample.
*Long sleep duration (>9 hours) is not reported (n=356).
†Frequent night awakenings was classified as ‘No’ if participant reported waking up while sleeping less than three times per week and ‘Yes’ if participant reported waking up while sleeping more than three times per night/day for more than three nights/days per week.
‡Cumulative sleep score was calculated by summing each participant's ‘yes’ response for each sleep characteristic. Scores range from 0 to 4, with poor sleep characteristics being combined into the category ‘2 to 4’.
§Recent sleep medication use was defined as use of the following medications within the past 4 weeks: inclusive of medication classes containing medications specifically used for sleep (directly affecting sleep), antihistamines and melatonin.
HS, high school; GED, general education diploma; BMI, body mass index.