Health Reports
Duration and quality of sleep among Canadians aged 18 to 79

by Jean-Philippe Chaput, Suzy L. Wong and Isabelle Michaud

Release date: September 20, 2017

Insufficient sleep (short duration and poor quality) is associated with a range of adverse health outcomes, including obesity, type 2 diabetes, cardiovascular disease, injuries, all-cause mortality, depression, irritability, and reduced well-being.Note 1 In today’s 24/7 world, insufficient sleep is common.Note 2Note 3 The factors that may be associated with insufficient sleep include exposure to artificial light at night, caffeine consumption, work demands, social commitments, and family dynamics (for example, working mothers and children with full agendas).Note 1 Sleep often receives relatively little attention as a component of a healthy lifestyle, and health care professionals and policy-makers tend not to regard it as a public health concern.Note 4

For adults aged 18 to 64 and seniors aged 65 or older, 7 to 9 hours and 7 to 8 hours of sleep per night, respectively, are recommended.Note 5 Findings from the 2005 General Social Survey (respondents aged 15 or older) showed that men slept significantly fewer hours per night than did women (8.1 versus 8.3; p < 0.05). However, women were more likely to report trouble falling asleep or staying asleep (35% versus 25%; p < 0.05).Note 6 The 2002 Canadian Community Health Survey: Mental Health and Well-being yielded similar results—35% of the population aged 15 or older had trouble going to sleep or staying asleep at least some of the time.Note 7

Sleep duration estimates for Canadian children and adolescents have recently been published,Note 8Note 9 but updated figures for adults are lacking. Information about the percentage of adults who sleep less than recommended and about the prevalence of poor sleep quality is important for surveillance and to inform health care providers, health policy makers and the general public. This study provides more recent estimates of sleep duration and quality in the context of sleep duration guidelines, based on the Canadian Health Measures Survey (CHMS) from 2007 to 2013 (see The data).

Percentage of 18- to 64-year-olds meeting sleep duration recommendations

During the 2007-to-2013 period, Canadians aged 18 to 64 averaged 7.12 hours of sleep per night (Table 1). About two-thirds reported the recommended 7 to 9 hours, and one-third, less than 7 hours. At these ages, sleeping more than 9 hours was rare (3.3%).

Consistent with previous Canadian findings,Note 6 women’s average sleep duration was significantly longer than that of men (7.24 versus 7.00 hours per night). However, 2007-to-2013 estimates were below those reported in 2005 (8.3 and 8.1 hours for women and men, respectively).Note 6 Variations in methodology (diary in 2005 versus self-reports in the 2007-to-2013 period) may explain some of this difference.

People aged 18 to 64 with higher household education and income were more likely to report sleeping the recommended number of hours per night, compared with those with less education and lower incomes.

Percentage of seniors meeting sleep duration recommendations

Seniors aged 65 to 79 averaged 7.24 hours of sleep per night (Table 2). About one-third of them reported fewer than the recommended 7 hours.

Compared with 18- to 64-year-olds, a larger percentage of seniors (about 15%) slept longer than the recommended 8-hour maximum. Long sleep duration in the elderly can signal a need for medical, neurological, or psychiatric evaluation.Note 5Note 10

In contrast to 18- to 64-year-olds, no significant sleep duration differences emerged between senior men and women. However, as was the case at younger ages, seniors in higher-income households were more likely than those in lower-income households to sleep the recommended number of hours per night. The pattern was similar for education, but did not reach statistical significance.

Sleep quality

According to results of the 2007-to-2013 CHMS, 43% of men and 55% of women aged 18 to 64 reported trouble going to sleep or staying asleep “sometimes/most of the time/all of the time” (Table 3). This was comparable to 2005, when a higher percentage of women than men reported trouble falling asleep or staying asleep (35% versus 25%).6 However, differences in the methodology used to collect sleep information preclude direct comparisons between studies.

Similarly, among seniors aged 65 to 79, women were more likely than men to report trouble going to sleep or staying asleep “sometimes/most of the time/all of the time” (59% versus 40%). Percentages for this sleep quality indicator did not differ statistically between 18- to 64-year-olds and 65- to 79-year-olds.

Three-quarters of seniors (75%) and about half (55%) of people aged 18 to 64 reported that sleep was refreshing “most of the time/all of the time.” Around a third (33% of 18- to 64-year-olds and 30% of seniors) reported difficulty staying awake during normal waking hours “sometimes/most of the time/all of the time.”

Sleep quality by sleep duration recommendation category

Men and women aged 18 to 64 who slept the recommended number of hours reported better sleep quality than did those who slept less or more than recommended (Table 4). They were more likely to report that sleep was usually refreshing, and less likely to report difficulty going to sleep, staying asleep, and staying awake during normal waking hours.

At ages 65 to 79, men and women who slept the recommended amount reported more refreshing sleep and less difficulty going to sleep and staying asleep, compared with those who slept fewer hours than recommended. As well, senior men and women who slept more hours than recommended reported less trouble going to sleep or staying asleep, staying awake and more refreshing sleep, compared with seniors who slept less than recommended.

Conclusion

Short sleep duration and poor sleep quality are prevalent among Canadian adults. About one-third sleep fewer hours per night than recommended for optimal physical and mental health. This group also experiences poor sleep quality more frequently than do those who sleep the recommended number of hours. Additional research is needed to determine the prevalence of adverse health outcomes among short and poor sleepers.

Acknowledgements

The authors thank the participants in the Canadian Health Measures Survey and all Statistics Canada staff involved in the operations of the survey.

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The data

Data source

The data are from cycles 1 to 3 (2007 through 2013) of the Canadian Health Measures Survey (CHMS), an ongoing nationally representative, cross-sectional survey of the household population. Residents of First Nations Reserves or other Aboriginal settlements, institutions and some remote regions, and full-time members of the Canadian Forces were excluded. Ethics approval for the CHMS was obtained from Health Canada’s Research Ethics Board.Note 11

Response rates for selected households were 69.6%, 75.9% and 74.1% for cycles 1, 2 and 3, respectively. From the responding households, 88.3% of participants completed the household questionnaire in cycle 1, 90.5% in cycle 2 and 88.4% in cycle 3. Combined dataNote 12 for respondents aged 18 to 79 from cycle 1 (2007 to 2009; n = 3,721),Note 13 cycle 2 (2009 to 2011; n = 3,866),Note 14 and cycle 3 (2012 to 2013; n = 3,389)Note 15 were used for the present analyses.

Definitions

Sleep duration was assessed with the question, “How many hours do you usually spend sleeping in a 24-hour period, excluding time spent resting?” Responses were rounded to the closest half hour. A total of 27 outliers/missing values were excluded from the analyses.

Sleep quality was assessed with three questions: (1) “How often do you have trouble going to sleep or staying asleep?”; (2) “How often do you find your sleep refreshing?”; and (3) “How often do you find it difficult to stay awake during your normal waking hours when you want to?” For each question, response options were: “Never,” “Rarely,” “Sometimes,” “Most of the time,” and “All of the time.” Those who responded “Don’t know” or who did not answer the question were removed from the analyses: (1) n=11; (2) n=9; (3) n=10.

Respondents were classified as meeting the recommended sleep duration range (7 to 9 hours per night at ages 18 to 64 and 7 to 8 hours per night at age 65 or older), sleeping less than recommended, or sleeping longer than recommended.Note 5

In addition to age group and sex, participants were examined by household education and household income. Household education was the highest level acquired by any member of the household; three categories were created (secondary graduation or less, secondary graduation but less than a bachelor’s degree, and a bachelor’ degree or more). Annual household income was reported by participants and collapsed into three levels: less than $40,000, $40,000 to less than $80,000, and $80,000 or more.

To account for the survey design, means and percentages were estimated using survey weights, and their variances were estimated using the survey bootstrap technique.Note 16Note 17 Then, 95% confidence intervals were calculated and small percentage confidence intervals were used by SUDAAN version 11 for estimated percentages ≤ 5%. T-tests were performed to compare means and proportions between different domains. P-values were adjusted for multiple comparisons using the False Discovery Rate (FDR) adjustment method. Differences between estimates were tested for statistical significance at a FDR adjusted p-value < 0.05. All analyses were conducted with SAS version 9.3 and SUDAAN version 11.

Limitations

Data from the Canadian Health Measures Survey do not include important sleep duration and quality characteristics such as timing, architecture (how individuals cycle through the stages of sleep), consistency, and continuity. Self-reports generally overestimate actual sleep duration and are subject to recall and/or social desirability bias.Note 18 Sleeping fewer hours than recommended does not necessarily adversely affect health.

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References
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