Table 1 Comparison of time series data among the OD (off-duty), 2NS (2 night shifts) and 4NS (4 night shifts) groups
Variables (mean ± SD) | Group (n= 23, 20, 16) | Time 1 | Time 2 | Time 3 | Time 4 | F(2,56) | P-value |
|---|---|---|---|---|---|---|---|
Sleep latency of MWT (min) | Off-duty | 24.3 ± 7.6 | 26.1 ± 7.0 | 23.4 ± 9.4 | 22.0 ± 8.3 | 11.03 | <0.001a |
Two night shifts | 17.0 ± 13.1 | 22.1 ± 15.1 | 18.8 ± 12.9 | 16.3 ± 14.8 | |||
Four night shifts | 8.2 ± 6.9 | 11.0 ± 12.2 | 13.1 ± 11.6 | 10.1 ± 13.7 | |||
Sleep latency of MSLT (min) | Off-duty | 13.2 ± 6.7 | 10.4 ± 6.4 | 8.6 ± 6.3 | 8.3 ± 5.9 | 1.18 | 0.314 |
Two night shifts | 10.0 ± 6.3 | 8.3 ± 6.1 | 8.0 ± 6.3 | 7.4 ± 5.2 | |||
Four night shifts | 7.5 ± 5.2 | 6.0 ± 4.6 | 8.5 ± 7.2 | 8.6 ± 7.4 | |||
State Anxiety Scale | Off-duty | 39.7 ± 7.1 | 38.4 ± 6.8 | 36.5 ± 8.1 | 35.4 ± 8.5 | 5.18 | 0.009b |
Two night shifts | 42.5 ± 8.0 | 43.6 ± 7.4 | 43.4 ± 7.3 | 42.2 ± 7.7 | |||
Four night shifts | 38.6 ± 7.0 | 36.8 ± 7.8 | 35.1 ± 7.5 | 33.9 ± 7.0 | |||
Stanford Sleepiness Scale | Off-duty | 3.2 ± 0.2 | 3.5 ± 0.2 | 3.8 ± 0.2 | 4.1 ± 0.2 | 0.81 | 0.451 |
Two night shifts | 3.4 ± 1.0 | 3.7 ± 1.1 | 4.2 ± 1.3 | 4.3 ± 1.3 | |||
Four night shifts | 3.4 ± 1.0 | 3.4 ± 1.0 | 3.4 ± 1.0 | 3.9 ± 1.3 | |||
Wisconsin Card Sorting Test | Â | Â | Â | Â | Â | Â | Â |
Number of perseverative errors | Off-duty | 11.6 ± 4.3 | 9.7 ± 2.9 | 10.7 ± 2.7 | 9.8 ± 2.5 | 0.98 | 0.383 |
Two night shifts | 12.1 ± 6.9 | 11.5 ± 6.4 | 12.1 ± 7.3 | 12.8 ± 11.0 | |||
Four night shifts | 9.9 ± 2.6 | 9.9 ± 1.9 | 10.25 ± 4.1 | 10.6 ± 3.1 | |||
Number of total errors | Off-duty | 23.5 ± 7.2 | 20.7 ± 5.7 | 18.3 ± 4.9 | 17.2 ± 5.1 | 1.44 | 0.246 |
Two night shifts | 24.7 ± 14.0 | 22.4 ± 12.0 | 23.0 ± 12.5 | 24.0 ± 13.7 | |||
Four night shifts | 21.2 ± 5.2 | 19.6 ± 5.3 | 19.6 ± 5.6 | 18.2 ± 4.5 |