Table 1.
Demographics of participants in each sleep strategy group, and timing, duration, quality, and regularity of sleep between consecutive night shifts.
| Morning | Delayed | Split | Mixed | Total | |
|---|---|---|---|---|---|
| N=7 | N=8 | N=8 | N=10 | N=33 | |
| Women/men [n] | 5/2 | 4/4 | 7/1 | 7/3 | 23/10 |
| Age [mean (sd)] | 34 (11) | 40 (15) | 38 (16) | 47 (15) | 40 (15) |
| Evening typesa [n] | 5 | 6 | 3 | 6 | 20 |
| Presence of 2nd job [n] | 3 | 5 | 3 | 4 | 15 |
| Participants with children [n] | 3 | 2 | 4 | 1 | 10 |
| Average number of children [mean (sd)] | 3.7 (2.1) | 2 (1.4) | 1.8 (1.5) | 1 | 2.3 (1.7 |
| Start time of NS [mean (sd)] | 19:27 (01:35) | 21:49 (00:56) | 21:55 (02:08) | 22:22 (1:22) | 21:30 (01:51) |
| End time of NS | 05:37 (01:44) | 06:30 (00:53) | 07:07 (00:40) | 07:07 (01:01) | 06:39 (01:13) |
| NS duration in hours [mean (sd)] | 10.1 (0.9) | 8.7 (1) | 9.2 (1.8) | 8.8 (1.5) | 9.1 (1.4) |
| Outcomes [mean (sd)] | |||||
| Start time 1st sleep | 08:01 (01:26) | 14:21 (01:14) | 09:39 (01:55) | 10:34 (02:31) | 10:43 (02:55) |
| End time 1st sleep | 14:12 (01:48) | 18:26 (01:58) | 13:05 (02:30) | 16:27 (03:06) | 15:38 (03:07) |
| Regularity of start time 1st sleep (min) | 30 (23) | 59 (22) | 34 (27) | 65 (48) | 49 (35) |
| Start time 2nd sleep | - | - | 17:17 (02:50) | 16:39 (03:15) | 16:58 (02:58) |
| End time 2nd sleep | - | - | 20:24 (02:47) | 19:27 (03:08) | 19:55 (02:54) |
| TST (min) | 353 (74) | 233 (140) | 363 (76) | 387 (109) | 337 (117) |
| Regularity of TST (min) | 52 (21) | 41 (24) | 33 (20) | 71 (28) | 50 (27) |
| Soundnessb | 3.7 (0.9) | 4 (1.7) | 3.5 (1.2) | 4.1 (1.2) | 3.8 (1.3) |
| Refreshedb | 2.9 (0.8) | 4.1 (1.2) | 2.3 (0.9) | 3.4 (1.3) | 3.2 (1.2) |
NS, night shifts; TST, total sleep time; n, number of participants; min, minutes.
a
Eveningness was measured with the question: ‘One hears about “morning” and “evening” types of people. Which one of these types do you consider yourself to be?’
b
Soundness of sleep and feeling refreshed after sleep were rated on a scale from 1–7.