Changes In Self-Reported Sleep Duration With Age - A 36-Year Longitudinal Study Of Finnish Adults
Background: Sleep deprivation is often claimed to be increasingly common, but most studies show small changes in sleep duration over the last decades. Our aim was to analyze long-term patterns in self-reported sleep duration in a population-based cohort.
Methods: Members of the Older Finnish Twin Cohort have responded to questionnaires in 1975 (N = 30,915 individuals, response rate 89%, mean age 36 years), 1981 (24,506, 84%, 41 years), 1990 (12,502, 77%, 44 years), and 2011 (8510, 72%, 60 years). Weibull regression models were used to model the effects of follow-up time and age simultaneously.
Results: Sleep duration has decreased in all adult age groups and in both genders. The mean duration was in men 7.57 hours in 1975 and 7.39 in 2011, and in women 7.69 and 7.37, respectively. The decrease was about 0.5 minutes in men and 0.9 in women per year of follow-up. In the age-group 18-34 years, mean sleep length was 7.69 hours in 1975 and 7.53 in 1990. Among 35-54-year-old it was 7.57 hours in 1975 and 7.34 in 2011, and in the age group of 55+ year olds 7.52 and 7.38, correspondingly. The change was largest in middle-aged group: about 23 minutes or about 0.6 minutes per year of follow-up.
Conclusions: There has been a slight decrease in mean sleep duration during the 36-year follow-up. Although the sleep duration was longer in 1970s and 1980s, the probable main cause for the change in this study population is the effect of aging.
Figure 1
Figure 2
Figure 3
This is a list of supplementary files associated with this preprint. Click to download.
Additional file #1: Title of data: FTC old cohort 1975 wave 1 questionnaire English translation Description of data: Unofficial translation of mailed questionnaire used in wave 1 of the older Finnish Twin Cohort in 1975, originals in Finnish and Swedish
Additional file #2: Title of data: FTC old cohort 1981 wave 1 questionnaire English translation Description of data: Unofficial translation of mailed questionnaire used in wave 2 of the older Finnish Twin Cohort in 1981, originals in Finnish and Swedish
Additional file #3: Title of data: FTC old cohort 1990 wave 3 questionnaire English translation Description of data: Unofficial translation of mailed questionnaire used in wave 3 of the older Finnish Twin Cohort in 1990, originals in Finnish and Swedish
Additional file #4: Title of data: FTC old cohort 2011 wave 4 questionnaire English translation Description of data: Unofficial translation of mailed questionnaire used in wave 4 of the older Finnish Twin Cohort in 2011, originals in Finnish and Swedish
Posted 14 Aug, 2020
On 09 Sep, 2020
On 11 Aug, 2020
On 11 Aug, 2020
On 06 Aug, 2020
Received 27 Jul, 2020
On 06 Jul, 2020
On 03 Jul, 2020
Received 03 Jul, 2020
On 02 Jul, 2020
Invitations sent on 02 Jul, 2020
On 01 Jul, 2020
On 01 Jul, 2020
On 30 Jun, 2020
Received 20 Jun, 2020
Received 06 Jun, 2020
On 26 May, 2020
Invitations sent on 20 May, 2020
On 20 May, 2020
On 30 Apr, 2020
On 29 Apr, 2020
On 29 Apr, 2020
On 29 Apr, 2020
Changes In Self-Reported Sleep Duration With Age - A 36-Year Longitudinal Study Of Finnish Adults
Posted 14 Aug, 2020
On 09 Sep, 2020
On 11 Aug, 2020
On 11 Aug, 2020
On 06 Aug, 2020
Received 27 Jul, 2020
On 06 Jul, 2020
On 03 Jul, 2020
Received 03 Jul, 2020
On 02 Jul, 2020
Invitations sent on 02 Jul, 2020
On 01 Jul, 2020
On 01 Jul, 2020
On 30 Jun, 2020
Received 20 Jun, 2020
Received 06 Jun, 2020
On 26 May, 2020
Invitations sent on 20 May, 2020
On 20 May, 2020
On 30 Apr, 2020
On 29 Apr, 2020
On 29 Apr, 2020
On 29 Apr, 2020
Background: Sleep deprivation is often claimed to be increasingly common, but most studies show small changes in sleep duration over the last decades. Our aim was to analyze long-term patterns in self-reported sleep duration in a population-based cohort.
Methods: Members of the Older Finnish Twin Cohort have responded to questionnaires in 1975 (N = 30,915 individuals, response rate 89%, mean age 36 years), 1981 (24,506, 84%, 41 years), 1990 (12,502, 77%, 44 years), and 2011 (8510, 72%, 60 years). Weibull regression models were used to model the effects of follow-up time and age simultaneously.
Results: Sleep duration has decreased in all adult age groups and in both genders. The mean duration was in men 7.57 hours in 1975 and 7.39 in 2011, and in women 7.69 and 7.37, respectively. The decrease was about 0.5 minutes in men and 0.9 in women per year of follow-up. In the age-group 18-34 years, mean sleep length was 7.69 hours in 1975 and 7.53 in 1990. Among 35-54-year-old it was 7.57 hours in 1975 and 7.34 in 2011, and in the age group of 55+ year olds 7.52 and 7.38, correspondingly. The change was largest in middle-aged group: about 23 minutes or about 0.6 minutes per year of follow-up.
Conclusions: There has been a slight decrease in mean sleep duration during the 36-year follow-up. Although the sleep duration was longer in 1970s and 1980s, the probable main cause for the change in this study population is the effect of aging.
Figure 1
Figure 2
Figure 3