Table 2.
Objective sleep parameters for whole study population
| Pre-lockdown | During lockdown | ||||
|---|---|---|---|---|---|
| Weekdays | Weekend | Weekdays | Weekend | ||
| Sleep duration and continuity | |||||
| Total sleep time (min) | 394 (361 to 425) | 411 (368 to 453) | 398 (363 to 431) | 408 (364 to 453) | |
| Delta TST (min) | Raw data* | Ref | 16 (−9 to 46.6) | 5 (−13 to 23) | 14 (−10 to 43) |
| Adjusted† | 18 (±1.9)‡ | 3.8 (±1.3)‡,§ | 16.8 (±1.8)‡,|| | ||
| Time in bed (min) | 456 (423 to 489) | 476 (439 to 514) | 463 (429 to 495) | 474 (432 to 518) | |
| Delta TIB (min) | Raw data | Ref | 17 (−8 to 51) | 5 (−10 to 24) | 14 (−9 to 45) |
| Adjusted | 20 (±2)‡ | 6 (±1.4)‡ | −8 (±2) | ||
| Sleep efficiency (%) | 88 (83 to 91) | 88 (82 to 92) | 87 (82 to 91) | 88 (83 to 92) | |
| Delta sleep efficiency (%) | Raw data | Ref | 0.4 (−2 to 2) | −0.3 (−2.3 to 2) | 0.1 (−2 to 3) |
| Adjusted | −0.06 (±0.2) | −0.31 (±0.17) | 0.52 (±0.25) | ||
| WASO (min) | 19 (10 to 36) | 20.3 (9 to 38) | 20 (9 to 36) | 19 (9 to 35) | |
| Delta WASO | Raw data | Ref | 0.2 (−6 to 7) | −0.2 (−6 to 5) | −0.6 (−8 to 7) |
| Adjusted | 1.3 (±0.7) | −0.14 (±0.6) | −1.1 (± 0.8) | ||
| Sleep architecture | |||||
| N2 (min) | 194 (166 to 225) | 202 (170 to 234) | 196 (170 to 227) | 203 (174 to 233) | |
| Delta N2 (min) | Raw data | Ref | 7 (−11 to 26) | 1.9 (−12 to 17) | 5.6 (−12 to 26) |
| Adjusted | 6.6 (±1.4)‡ | 2 (±1)‡ | 7 (±1.3) | ||
| N3 (min) | 80 (59 to 100) | 81 (60 to 101) | 80 (59 to 99) | 81 (59 to 99) | |
| Delta N3 (min) | Raw data | Ref | −0.3 (−8 to 7) | −1.5 (−9 to 5) | −1.5 (−10 to 8) |
| Adjusted | −0.05 (±0.55) | −1.75 (±0.51)‡ | −1.24 (±0.63) | ||
| REM (min) | 113 (88 to 134) | 124 (98 to 148) | 115 (95 to 138) | 120 (98 to 147) | |
| Delta REM (min) | Raw data | Ref | 10 (−3 to 23) | 4 (−7 to 15) | 10 (−4 to 25) |
| Adjusted | 3.7 (±0.8)‡ | 11.4 (±1)‡ | 10.7 (±1)‡ | ||
| SOD (min) | 19 (13 to 27) | 17 (12 to 24) | 20 (14 to 28) | 18. (13 to 26) | |
| Delta SOD (min) | Raw data | Ref | −1.4 (−6 to 2) | 1.2 (−2.3 to 6) | −0.1 (−4 to 5) |
| Adjusted | −0.9 (±0.5)‡ | 1.8 (±0.3)‡ | 0.6 (±0.4) |
WASO = wake time after sleep onset; SOD = sleep onset delay/latency (time from lights out to falling asleep).
*Raw data: data are presented as the median difference and interquartile range with weekday pre-lockdown values as reference.
†Adjusted: estimation of the mixed model with a random effect for the user, adjusted on age and gender (standard error).
‡Significant effect of the lockdown or interaction between weekend and lockdown compared to weekday pre-lockdown (reference).
§This corresponds to the lockdown effect.
||This corresponds to the interaction term between weekend and lockdown and can be interpreted as the cumulative effect of the weekend during lockdown compared to the week pre-lockdown.