Codes and Frequencies
For sample adults, HRSLEEP reports how many hours, on average, the respondent sleeps per day. For surveys prior to 2004, interviewers were instructed to write down responses verbatim. From 2004 forward, interviewers were instructed to report the hours of sleep in whole numbers, rounding values of 30 minutes or more UP to the nearest hour or otherwise rounding down. IPUMS NHIS recodes the values from the earlier surveys into whole number values, following the same rules as 2004 forward.
Beginning in 2020, HRSLEEP is one of a set of rotating core variables on sleep duration and quality collected by the NHIS every other year. In addition to HRSLEEP, other variables in the sleep rotating core include:
- SLEEPRESTFRQ: How often woke up feeling well rested, past 30 days
- SLEEPFALLFRQ: How often had trouble falling asleep, past 30 days
- SLEEPSTAYFRQ: How often had trouble staying asleep, past 30 days
- SLEEPMEDFRQ: How often took medication for sleep, past 30 days
- CSLEEPREST: How often wake up feeling well rested in a typical school week
- CSLEEPGETUP: How often difficult to get out of bed in the morning in a typical school week
- CSLEEPTIRED: How often complain of being tired during the day in a typical school week
- CSLEEPNAPS: How often nap or fall asleep during the day in a typical school week
- CSLEEPBEDTIME: How often have a regular bedtime on school nights in a typical school week
- CSLEEPWKTIME: How often wake up at same time in a typical school week
A set of questions on sleep were asked annually of sample adults in 2004-2018 that are similar to those asked beginning in 2020 but differ in the reference period (past week vs. past 30 days) and the structure of the response categories (number of days in past week vs. how often in the past 30 days). These variables include:
- SLEEPREST: Days woke up feeling rested, past week
- SLEEPFALL: Number of times having trouble falling asleep, past week
- SLEEPSTAY: Number of times having trouble staying asleep, past week
- SLEEPMEDS: Number of times taking medication for sleep, past week
In addition to changes in how responses were collected, there were also changes in how respondents were asked about the number of hours they sleep per day and other, broader changes in the NHIS questionnaire that create comparability challenges. In 1977 and 1983, respondents were asked about hours slept "at night" while for all later years, the survey asked about hours slept in a 24 hour period.
However, the 1977 Field Representative's Manual notes that if the person works at night, "hours of sleep" referred to the person's normal sleeping hours. Similarly, the 1983 Manual defines "sleep at night" to be the number of hours usually slept, "even if the sample person sleeps during the day."
The question for HRSLEEP in 1977 was asked for a sub-sample of randomly selected persons age 20 and over; NHIS automatically classifies persons who were selected but did not complete the questions as responding "unknown" for this variable. Users may choose to use this variable in combination with SUBSRESP77, which reports the person's sub-sample status in 1977.
Questionnaire design changes introduced in 2019 limit comparability with earlier years. The NHIS questionnaire was substantially redesigned in 2019 to introduce a different data collection structure and new content. For more information on changes in terminology, universes, and data collection methods beginning in 2019, please see the user note.
- 1977: One third of persons age 20+.
- 1983; 1985; 1990: Sample persons age 18+.
- 2004-2018: Sample adults age 18+.
- 2020: Sample adults age 18+.
- 1977, 1983, 1985, 1990, 2004-2018, 2020
- 1985, 1990, 2004-2018, 2020 : SAMPWEIGHT
- 1983 : SUPP1WT
- 1977 : SUB77WT