TABLE 2.
ORs (95% CIs) for the Association Between Demographic Variables and Probability of Regular ≥7 Hours of Sleep Per Night and Regularly Getting Adequate Sleep, By Time Period
| 1991–1995 | 1996–2000 | 2001–2005 | 2006–2010 | 2011–2012 | Interactions | ||
|---|---|---|---|---|---|---|---|
| Get 7 h of sleep | |||||||
| n = | n = 78 444 | n = 57 735 | n = 55 484 | n = 56 646 | n = 22 590 | ||
| Gender | Female | 0.68 (0.66–0.7) | 0.68 (0.66–0.71) | 0.7 (0.67–0.72) | 0.67 (0.64–0.69) | 0.66 (0.63–0.7) | 0.84 |
| Male | 1 | 1 | 1 | 1 | 1 | ||
| Race | Black | 0.99 (0.95–1.04) | 0.97 (0.92–1.02) | 1.07 (1.01–1.12) | 0.84 (0.79–0.88) | 0.89 (0.81–0.97) | 0.05 |
| Hispanic | 0.9 (0.85–0.94) | 0.99 (0.93–1.04) | 0.95 (0.9–1) | 0.87 (0.83–0.91) | 0.92 (0.85–0.99) | 0.90 | |
| Asian | 0.86 (0.79–0.93) | 0.83 (0.76–0.9) | 0.79 (0.73–0.87) | 0.75 (0.69–0.81) | 0.99 (0.87–1.12) | 0.33 | |
| Other | 1.03 (0.98–1.09) | 1.06 (0.99–1.13) | 1.05 (0.98–1.12) | 0.83 (0.78–0.88) | 0.94 (0.86–1.02) | 0.99 | |
| White | 1 | 1 | 1 | 1 | 1 | ||
| Urbanicity | Nonurban | 1.12 (1.09–1.16) | 1.11 (1.07–1.16) | 1.06 (1.01–1.1) | 1.11 (1.06–1.15) | 1.15 (1.08–1.22) | 0.93 |
| Urban | 1 | 1 | 1 | 1 | 1 | ||
| Highest parental education | >High school | 1.33 (1.26–1.41) | 1.25 (1.17–1.34) | 1.22 (1.14–1.32) | 1.34 (1.25–1.44) | 1.34 (1.2–1.5) | 0.10 |
| High school | 1.22 (1.15–1.3) | 1.2 (1.11–1.29) | 1.07 (0.99–1.16) | 1.15 (1.07–1.25) | 1.15 (1.01–1.31) | 0.02 | |
| <High school | 1 | 1 | 1 | 1 | 1 | ||
| Age, y | 18–19 | 0.29 (0.27–0.31) | 0.27 (0.25–0.29) | 0.25 (0.23–0.27) | 0.29 (0.27–0.32) | 0.32 (0.28–0.35) | <0.01 |
| 16–17 | 0.46 (0.44–0.48) | 0.42 (0.4–0.44) | 0.39 (0.38–0.42) | 0.45 (0.42–0.47) | 0.43 (0.39–0.46) | 0.09 | |
| 14–15 | 0.7 (0.67–0.73) | 0.7 (0.66–0.73) | 0.67 (0.64–0.71) | 0.69 (0.66–0.73) | 0.65 (0.6–0.7) | 0.01 | |
| 12–13 | 1 | 1 | 1 | 1 | 1 | ||
| Get adequate sleep | |||||||
| n = 78 374 | n = 57 688 | n = 55 450 | n = 56 617 | n = 22 590 | |||
| Gender | Female | 0.81 (0.78–0.83) | 0.81 (0.79–0.84) | 0.87 (0.83–0.9) | 0.82 (0.79–0.85) | 0.82 (0.77–0.87) | 0.18 |
| Male | 1 | 1 | 1 | 1 | 1 | ||
| Race | Black | 1.58 (1.51–1.65) | 1.55 (1.47–1.64) | 1.52 (1.44–1.61) | 1.39 (1.31–1.48) | 1.15 (1.05–1.26) | 0.03 |
| Hispanic | 1.38 (1.31–1.46) | 1.48 (1.39–1.56) | 1.39 (1.31–1.47) | 1.3 (1.23–1.37) | 1.1 (1.01–1.2) | <0.01 | |
| Asian | 0.89 (0.81–0.98) | 0.9 (0.82–1) | 0.81 (0.73–0.9) | 0.85 (0.77–0.93) | 0.92 (0.8–1.06) | 0.03 | |
| Other | 1.27 (1.2–1.35) | 1.37 (1.28–1.47) | 1.33 (1.24–1.43) | 1.08 (1.01–1.15) | 0.98 (0.89–1.07) | 0.29 | |
| White | 1 | 1 | 1 | 1 | 1 | ||
| Urbanicity | Nonurban | 1.19 (1.15–1.23) | 1.18 (1.13–1.23) | 1.15 (1.09–1.2) | 1.14 (1.09–1.19) | 1.12 (1.05–1.2) | 0.94 |
| Urban | 1 | 1 | 1 | 1 | 1 | ||
| Highest parental education | >High school | 0.75 (0.7–0.8) | 0.65 (0.6–0.7) | 0.69 (0.64–0.74) | 0.76 (0.71–0.82) | 0.92 (0.81–1.04) | <0.01 |
| High school | 0.88 (0.83–0.94) | 0.85 (0.79–0.92) | 0.85 (0.78–0.93) | 0.86 (0.79–0.94) | 1.05 (0.91–1.21) | 0.99 | |
| <High school | 1 | 1 | 1 | 1 | 1 | ||
| Age, y | 18–19 | 0.43 (0.4–0.46) | 0.41 (0.38–0.44) | 0.44 (0.41–0.48) | 0.41 (0.38–0.45) | 0.44 (0.39–0.49) | 0.38 |
| 16–17 | 0.51 (0.49–0.53) | 0.5 (0.48–0.53) | 0.54 (0.51–0.57) | 0.52 (0.49–0.55) | 0.46 (0.42–0.5) | 0.36 | |
| 14–15 | 0.74 (0.72–0.77) | 0.76 (0.72–0.8) | 0.79 (0.75–0.83) | 0.77 (0.73–0.81) | 0.68 (0.63–0.74) | 0.07 | |
| 12–13 | 1 | 1 | 1 | 1 | 1 | 0.18 | |
The interaction with each variable was tested by year, with year modeled as a continuous variable to determine whether the magnitude of the odds ratios (ORs) were increasing or decreasing over time. CI, confidence interval.