Table 1.
Source | Study Design | Sample | Results | Limitations |
---|---|---|---|---|
NSF, 200512 | Random interviews | Sleep in America poll | Americans sleeping ≤ 8 h in 2001, 38%; 2002, 30%; in 2005, 26% | Response bias of self-reports |
Stamatakis et al, 20075 | Questionnaire data | Alameda County Health and Ways of Living Study (1965, 1974, 1983, 1994, 1999), n=6928 | Overall percentage of short sleepers increased over time for African Americans (26% in 1965 to 54% in 1999), Hispanics (12% in 1965 to 37% in 1999) and whites (15% in 1965 to 25% in 1999). | Response bias of self-reports |
Knutson et al, 201017 | Meta-analysis of 8 national studies, 1975–2006 | American's Use of Time Series (1975,1985,199–99); Environmental Protection Agency Time Use Study (1992–94); American Time Use Survey (ATUS) (2003,2004,2005,2006) | Odds of short sleep higher for full-time workers, those with some college education, and African Americans. Short sleepers were 7.6% in 1975, 9.3% in 2006 | Time diaries, total daily sleep not limited to sleep at night |
Luckhaupt, 201014 | Cross-sectional epidemiologic survey | 2004–07 National Health Interview Survey (NHIS);, employed adults; ages ≤18 y, n=66,099 | Proportion of 6 h sleepers was 30.7% in 2004 (95% CI: 1.03–1.13) and 28.4% in 2007; mean proportion of short sleepers 37.2% (95% Cl: 1.24–1.35) for blacks and 28.8% for whites | Sample limited to the employed; response bias of self-reports |
Robinson et al, 201016 | Time diaries | 2003–2007 ATUS, ages 18–64 y | Sleep in America increased; in 1965, 56 hrs/week, in 2007, 59 hr/week | Weekly estimates, does not limit sleep to nightly sleep or does not account for making up for lost sleep during the weekend. |
Abbreviations: CI, confidence interval