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Table 3 Comparison of sleep timing and duration among the JFCT members

From: Sleep patterns among shift-working flight controllers of the International Space Station: an observational study on the JAXA Flight Control Team

  DW ONEW SWSD− SWSD+ One-factor ANOVA or chi-square test
F or χ 2 value p value
Nights before days off Bedtime (A) 23:28 ± 1:03 23:20 ± 1:03 0:28 ± 0:45 a 23:28 ± 0:59 4.268 0.01
Wake time (B) 7:15 ± 0:45 7:03 ± 1:09 7:40 ± 0:43 7:11 ± 0:51 1.257 0.301
Length from A to B 7:47 ± 0:25 7:43 ± 0:50 7:12 ± 0:34 7:44 ± 1:04 1.623 0.198
Between consecutive day shifts Bedtime (A) 22:56 ± 0:33 23:09 ± 0:46 23:43 ± 0:56 22:58 ± 0:56 2.54 0.068
Wake time (B) 5:34 ± 0:40 6:09 ± 0:28 6:13 ± 0:36 5:53 ± 0:41 2.537 0.069
Length from A to B 6:38 ± 0:21 7:00 ± 0:42 6:30 ± 0:54 6:55 ± 0:57 1.182 0.327
Between consecutive evening shifts Bedtime (A)   3:25 ± 1:24 3:10 ± 0:51 3:21 ± 0:49 0.23 0.796
Wake time (B)   9:30 ± 2:06 9:50 ± 1:44 9:28 ± 1:29 0.19 0.828
Length from A to B   6:05 ± 1:07 6:39 ± 1:16 6:06 ± 0:59 1.233 0.302
Total time allocated for sleep   6:18 ± 0:45 6:58 ± 0:58 6:28 ± 0:36 2.754 0.076
Between consecutive night shifts Bedtime (A)   12:30 ± 1:54 12:17 ± 2:31 12:12 ± 2:25 0.054 0.948
Wake time (B)   18:00 ± 2:40 17:36 ± 3:20 17:54 ± 3:52 0.054 0.947
Length from A to B   5:30 ± 1:19 5:19 ± 1:40 5:42 ± 1:59 0.19 0.828
Total time allocated for sleep   6:25 ± 1:25 6:42 ± 1:44 6:42 ± 1:15 0.152 0.860
Percentages of evening nappers (napping after 7 p.m.)   45.5 % (5) 43.8 % (7) 28.6 % (4) 4.901 0.086
  1. The values denote mean ± standard deviation or percentages and number of subjects. p values denote the results of the one-factor ANOVA or Pearson chi-square test among the subjects groups. The total time allocated for sleep is the sum of the major sleep period and additional naps
  2. aSignificantly different from ONEW