Table 2.
Overall Changes to Sleep Duration, Timing and Mid-sleep on Workdays and Free Days during Lockdown and Mental Health Score Broken Down by Diurnal Preference
| Variable | Situation | Whole sample | Definite morning | Moderate morning | Moderate evening | Definite evening |
|---|---|---|---|---|---|---|
| Sample size no. [%] | NA | 375 [100] | 69 [18.4] | 127 [33.9] | 120 [32.0] | 59 [15.7] |
| Sleep need (h) | NA | 8.13 (0.07) | 7.72 (0.18) | 8.14 (0.11) | 8.32 (0.09) | 8.22 (0.19) |
| Time in bed (h) | Pre-COVID | 8.47 (0.06) | 8.23 (0.14) | 8.48 (0.10) | 8.55 (0.12) | 8.58 (0.15) |
| During lockdown | 9.32 (0.07)*** | 8.93 (0.15)*** | 9.28 (0.13)*** | 9.43 (0.11)*** | 9.64 (0.22)*** | |
| Total sleep time (h) | Pre-COVID | 7.52 (0.05) | 7.36 (0.13) | 7.60 (0.08) | 7.52 (0.08) | 7.52 (0.13) |
| During lockdown | 8.06 (0.06)*** | 7.82 (0.14)*** | 8.06 (0.11)*** | 8.15 (0.10)*** | 8.14 (0.19)** | |
| Sleep onset workdays (hh:mm) | Pre-COVID | 23:04 (00:03) | 22:35 (00:06) | 22:47 (00:05) | 23:14 (00:05) | 23:53 (00:09) |
| During lockdown | 23:49 (00:05)*** | 22:47 (00:10) | 23:28 (00:07)*** | 00:08 (00:08)*** | 01:08 (00:14)*** | |
| Wake up time workdays (hh:mm) | Pre-COVID | 06:55 (00:04) | 06:09 (00:06) | 06:45 (00:07) | 07:10 (00:06) | 07:43 (00:10) |
| During lockdown | 07:47 (00:05)*** | 06:49 (00:08)*** | 07:28 (00:07)*** | 08:10 (00:08)*** | 08:50 (00:14)*** | |
| Sleep onset free days (hh:mm) | Pre-COVID | 23:47 (00:04) | 23:01 (00:07) | 23:26 (00:07) | 00:03 (00:06) | 00:56 (00:10) |
| During lockdown | 00:24 (00:05)*** | 23:15 (00:10) | 00:00 (00:08)*** | 00:39 (00:08)*** | 02:04 (00:14)*** | |
| Wake up time free days (hh:mm) | Pre-COVID | 08:26 (00:04) | 07:17 (00:07) | 08:10 (00:07) | 08:45 (00:06) | 09:40 (00:10) |
| During lockdown | 08:47 (00:05)*** | 07:27 (00:08) | 08:24 (00:08)** | 9:09 (00:08)*** | 10:27 (00:14)*** | |
| Mid-sleep workdays (hh:mm) | Pre-COVID | 03:00 (00:03) | 02:22 (00:05) | 02:46 (00:05) | 03:12 (00:04) | 03:48 (00:08) |
| During lockdown | 03:48 (00:05)*** | 02:48 (00:07)** | 03:28 (00:07)*** | 04:09 (00:07)*** | 04:59 (00:13)*** | |
| Mid-sleep free days (hh:mm) | Pre-COVID | 04:06 (00:04) | 03:09 (00:06) | 03:48 (00:06) | 04:24 (00:05) | 05:18 (00:08) |
| During lockdown | 04:35 (00:05)*** | 03:21 (00:08)* | 04:12 (00:07)*** | 04:54 (00:07)*** | 06:16 (00:13)*** | |
| Degree of change in mid-sleep (h) | Workdays | 0.81 (0.06) | 0.43 (0.12) | 0.70 (0.10) | 0.95 (0.11) | 1.18 (0.19) |
| Free days | 0.48 (0.05)*** | 0.19 (0.10)** | 0.40 (0.09)*** | 0.51 (0.09)*** | 0.96 (0.16) | |
| Social jetlag (h) | Pre-COVID | 1.11 (0.04) | 0.79 (0.08) | 1.03 (0.07) | 1.19 (0.07) | 1.50 (0.11) |
| During lockdown | 0.79 (0.04)*** | 0.55 (0.07)** | 0.73 (0.06)*** | 0.75 (0.09)*** | 1.28 (0.12) | |
| Sleep latency (min) | Pre-COVID | 23.72 (0.89) | 21.71 (1.84) | 21.36 (1.22) | 26.05 (1.79) | 26.42 (2.58) |
| During lockdown | 32.29 (1.33)*** | 28.68 (3.24)* | 28.84 (2.12)*** | 34.44 (2.36)*** | 39.56 (3.50)*** | |
| Daytime sleepiness | Pre-COVID | 3.48 (0.10) | 3.19 (0.22) | 3.44 (0.18) | 3.64 (0.17) | 3.59 (0.26) |
| During lockdown | 3.80 (0.12)** | 3.26 (0.25) | 3.51 (0.19) | 4.03 (0.21) | 4.61 (0.28)** | |
| Mental health (score) | PHQ-4 | 3.01 (0.13) | 2.81 (0.29) | 2.50 (0.22) | 3.25 (0.23) | 3.85 (0.37) |
| PSS-4 | 5.88 (0.14) | 5.74 (0.28) | 5.46 (0.25) | 6.03 (0.25) | 6.63 (0.40) |
Data is shown as mean (SEM) or no. [%]. Significant differences between the time points are shown in bold with a * denoting p < 0.05, ** denoting p < 0.01, and *** denoting p < 0.001.