Table 2.
Mean hours of sleep in the last week (h/week) (n = 31,806).
| Characteristics | n | Male | Female | Total | p |
|---|---|---|---|---|---|
| 2013–2014 cohort (9–15 Dec) | 3009 | 7.14 (0.88) | 6.99 (0.93) | 7.09 (0.90) | 0.001 |
| 2013–2014 cohort (5–11 May) | 2970 | 7.32 (0.95) | 7.17 (0.99) | 7.27 (0.97) | 0.001 |
| 2014–2015 cohort (6–12 Oct) | 2996 | 7.07 (0.77) | 6.94 (0.78) | 7.03 (0.78) | 0.001 |
| 2014–2015 cohort (24 Feb–2 Mar) | 3002 | 7.94 (1.12) | 8.01 (1.35) | 7.97 (1.21) | 0.605 |
| 2014–2015 cohort (4–10 May) | 2157 | 7.47 (1.14) | 7.34 (1.15) | 7.43 (1.15) | 0.001 |
| 2015–2016 cohort (14–20 Sep) | 2922 | 7.07 (0.71) | 6.94 (0.76) | 7.03 (0.73) | 0.001 |
| 2015–2016 cohort (2–8 May) | 3007 | 7.44 (1.50) | 7.18 (1.09) | 7.35 (1.39) | 0.001 |
| 2016–2017 cohort (21–27 Nov) | 3192 | 7.18 (0.93) | 7.02 (0.94) | 7.13 (0.93) | 0.001 |
| 2016–2017 cohort (15–21 May) | 2113 | 7.22 (0.97) | 7.12 (1.03) | 7.19 (0.98) | 0.038 |
| 2017–2018 cohort (13–19 Nov) | 3056 | 7.06 (1.01) | 6.84 (1.00) | 6.99 (1.01) | 0.001 |
| 2017–2018 cohort (30 Apr–6 May) | 3382 | 7.19 (1.09) | 7.05 (1.37) | 7.15 (1.19) | 0.001 |
Note: p-values come from t-tests.