Table 1

Participant characteristics: data from 5 British cohort studies

Cohort study, birth year
20011990197019581946
Cohort characteristics and risk factors
 Sample size, n21641661380445741080
 Age in years19–2030–31506274
 Men (%)49.443.651.350.950.4
 Father’s social class, % manual23.1%37.7%58.3%63.1%67.3%
 Education attainment, % GCSEs–none47.3%35.9%46.6%49.2%70.8%
 Financial difficulties, % difficult18.1%16.1%21.0%13.4%4.3%
Outcomes
 Pre: sleep (no of hours/day), mean (SD)7.5 (1.4)7.1 (1.1)6.8 (1.2)7.0 (1.2)6.9 (1.2)
 During: sleep (no of hours/day), mean (SD)8.1 (1.9)7.4 (1.5)6.9 (1.5)7.0 (1.4)6.9 (1.3)
 Pre: sleep, % atypical (<6 >9 hours/night)12.9%6.9%12.0%10.0%10.8%
 During: sleep, % atypical (<6 >9 hours/night)31.7%16.5%18.4%15.6%16.1%
 Pre: exercise (no of days/week), mean (SD)3.0 (2.1)2.7 (2.1)3.0 (2.2)3.3 (2.4)3.2 (2.4)
 During: exercise (no of days/week), mean (SD)3.1 (2.3)2.9 (2.2)3.3 (2.4)3.5 (2.6)3.3 (2.6)
 Pre: exercise (% 0–2 days/week)28.8%32.0%29.7%26.9%29.5%
 During: exercise (% 0–2 days/week)30.4%32.5%29.2%29.1%30.8%
 Pre: alcohol intake, % never15.3%20.5%16.1%16.2%18.5%
 During: alcohol intake, % never27.7%25.2%19.0%20.9%20.7%
 Pre: alcohol intake, % high risk32.6%16.0%17.3%17.2%14.2%
 During: alcohol intake, % high risk13.0%12.7%21.7%17.4%14.6%
 Pre: fruit/veg intake (no of portions), mean (SD)3.0 (1.5)3.4 (1.5)3.5 (1.6)3.7 (1.5)4.0 (1.4)
 During: fruit/veg intake (no of portions), mean (SD)3.2 (1.6)3.5 (1.6)3.5 (1.6)3.7 (1.6)4.0 (1.4)
 Pre: fruit/veg intake (% 0–2 portions)39.4%27.0%27.4%24.3%16.3%
 During: fruit/veg intake (% 0–2 portions)34.4%26.9%27.3%24.5%14.7%
  • Estimates are weighted to account for survey non-response. High-risk drinking is consuming more than 14 drinks a week or more than 5 drinks in a typical drinking day.