Trends in the Prevalence of Short Sleepers in the USA: 1975–2006

STUDY OBJECTIVES: To determine (1) whether short sleep has increased over 31 years; (2) whether trends in short sleep differed by employment status; (3) which sociodemographic factors predict short sleep; and (4) how short sleepers spend their time. DESIGN: Time diaries from eight national studies conducted between 1975 and 2006. PATIENTS OR PARTICIPANTS: U.S. adults > or = 18 years. MEASUREMENTS AND RESULTS: Short sleepers were defined as those reporting or = 65 years, Asians, Hispanics, and married people. The odds were higher for full-time workers, those with some college education, and African Americans. Short sleepers in all employment categories spent more time on personal activities. Short sleepers who were full- and part-time workers spent much more time working. CONCLUSIONS: Based on time diaries, the increase in the odds of short sleep over the past 31 years was significant among full-time workers only. Work hours are much longer for full-time workers sleeping < 6 hours.