Table 2 Characteristics of black participants in the NHIS study (1977-2009)
From: Differential increase in prevalence estimates of inadequate sleep among black and white Americans
Characteristics | 1977 | 1983 | 1985 | 1990 | 2004 | 2005 | 2006 | 2007 | 2008 | 2009 |
|---|---|---|---|---|---|---|---|---|---|---|
N | 1,703 | 942a | 4,270 | 4,922 | 3,501 | 3,496 | 3,285 | 2,977 | 2,727 | 3,738 |
Gender, Female (%) | 59.1 | 59.5 | 55.3 | 54.8 | 54.2 | 53.1 | 53.6 | 53.2 | 54.5 | 54.5 |
Age, years (mean ± SD) | 40 ± 15 | 38 ± 15 | 38 ± 19 | 38 ± 18 | 40 ± 17 | 40 ± 17 | 40 ± 18 | 40 ± 17 | 40 ± 18 | 41 ± 16 |
Education, ≥ HS (%) | 55.2 | 64.9 | 67.0 | 72.3 | 84.5 | 85.2 | 86.2 | 86.4 | 87.3 | 86.9 |
Marital status (%) | Â | Â | Â | Â | Â | Â | Â | Â | Â | Â |
 Married | 50.3 | 47.0 | 46.7 | 45.9 | 38.9 | 37.7 | 37.9 | 37.4 | 35.3 | 36.0 |
 Widowed, Divorced & Separated | 29.3 | 21.8 | 20.6 | 21.5 | 22.4 | 22.0 | 21.2 | 22.2 | 20.6 | 21.0 |
 Single | 20.4 | 31.2 | 32.7 | 32.6 | 38.7 | 40.3 | 40.9 | 40.4 | 44.1 | 43.0 |
Family income, ≥35K (%) | -- | 10.3 | 13.5 | 25.4 | 45.9 | 47.2 | 45.3 | 52.3 | 54.9 | 53.0 |
Poverty status, below (%) | -- | 22.8 | 27.9 | 23.5 | 18.5 | 20.4 | 21.6 | 23.1 | 19.9 | 23.0 |
Ever smoked, yes (%) | 57.2 | 50.5 | 52.1 | 43.5 | 32.8 | 34.7 | 34.3 | 33.3 | 34.9 | 35.2 |
Alcohol consumption | Â | Â | Â | Â | Â | Â | Â | Â | Â | Â |
 Never drinkers | -- | -- | -- | 25.4 | 36.2 | 36.4 | 34.1 | 31.9 | 28.9 | 27.1 |
 Former drinkers | -- | -- | -- | 9.3 | 13.2 | 13.0 | 13.8 | 14.5 | 14.9 | 15.1 |
 Current drinkers | -- | -- | -- | 65.4 | 50.6 | 50.6 | 52.2 | 53.6 | 56.2 | 57.8 |
Body mass index (mean ± SD) | 25.8 ± 5.4 | 25.6 ± 5.2 | 25.6 ± 6.2 | 26.5 ± 6.4 | 28.0 ± 6.3 | 27.8 ± 6.3 | 28.3 ± 7.2 | 28.4 ± 7.1 | 28.4 ± 7.3 | 28.7 ± 8.2 |
Obesity (BMI ≥ 30 kg/m2) | 16.9 | 17.6 | 16.1 | 21.3 | 31.9 | 31.3 | 32.9 | 34.4 | 35.9 | 36.7 |
Physical activity, yes (%) | -- | -- | -- | -- | 11.5 | 11.5 | 10.9 | 11.9 | 13.6 | 13.7 |
Emotional stress, yes (%) | -- | -- | -- | -- | 3.6 | 3.2 | 3.7 | 2.6 | 3.6 | 4.0 |
Comorbid conditions: | Â | Â | Â | Â | Â | Â | Â | Â | Â | Â |
Diabetes | -- | 5.8 | -- | -- | 8.3 | 8.7 | 9.7 | 9.5 | 9.4 | 10.7 |
Hypertension | -- | 31.2 | 28.1 | 28.0 | 27.8 | 27.5 | 28.9 | 29.9 | 30.6 | 30.9 |
Cancer | -- | 0.3 | -- | -- | 2.7 | 2.4 | 2.8 | 2.9 | 2.6 | 3.2 |
Coronary heart disease | -- | 1.4 | -- | -- | 2.2 | 2.5 | 2.5 | 2.6 | 2.3 | 2.9 |
Heart attack (MI) | -- | -- | -- | -- | 1.4 | 1.6 | 2.1 | 1.6 | 2.3 | 2.5 |
Stroke | -- | 1.1 | 1.3 | 1.8 | 2.1 | 2.0 | 2.7 | 2.4 | 2.5 | 2.4 |
Kidney disease | -- | -- | -- | -- | 1.8 | 1.9 | 1.5 | 2.6 | 1.6 | 1.6 |
Sleep measures: | Â | Â | Â | Â | Â | Â | Â | Â | Â | Â |
Hours of sleep (mean ± SD) | 7.4 ± 1.6 | 7.2 ± 1.6 | 7.5 ± 2.3 | 7.4 ± 2.4 | 7.1 ± 2.3 | 7.1 ± 1.7 | 7.0 ± 1.8 | 7.1 ± 1.8 | 7.1 ± 2.1 | 7.0 ± 2.3 |
Categories of sleep quantity | Â | Â | Â | Â | Â | Â | Â | Â | Â | Â |
 Very short sleep | 3.3 | 4.4 | 2.4 | 2.4 | 3.3 | 3.1 | 3.7 | 3.6 | 3.8 | 4.0 |
 Short sleep | 24.6 | 27.8 | 25.8 | 27.4 | 31.7 | 31.7 | 32.6 | 30.9 | 33.2 | 33.7 |
 Normal sleep | 56.0 | 55.9 | 54.6 | 56.2 | 55.5 | 55.7 | 55.4 | 56.5 | 53.9 | 52.9 |
 Long sleep | 16.1 | 11.9 | 17.2 | 14.0 | 9.4 | 9.4 | 8.3 | 9.0 | 9.1 | 9.4 |