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The impact of returning to a daytime schedule on sleep, performance and mood after simulated fixed and rotating split shift schedules Cover

The impact of returning to a daytime schedule on sleep, performance and mood after simulated fixed and rotating split shift schedules

Eat, Sleep, Work
Volume 1 (2020): Issue 1 (October 2020)
By: S Centofanti,  M Short,  CJ Hilditch,  J Dorrian,  M Kohler and  S Banks  
Open Access
|Sep 2022

Figures & Tables

Figure 1.

Protocol schematics with 24h time across the x-axes. Black bars represent sleep opportunities. Grey bars represent wake time, and boxed grey bars represent on-shift periods. Unshaded crosses represent practice neurobehavioural test bouts and shaded crosses represent analysed neurobehavioural test bouts. All conditions undertook two baseline nights with 10h TIB sleep opportunities, four 24h periods on a Fixed A, Fixed B or Rotating shift schedule with 20h TIB per 48h, and two days back on a day schedule with 10h TIB ‘recovery sleep’ opportunities.
Protocol schematics with 24h time across the x-axes. Black bars represent sleep opportunities. Grey bars represent wake time, and boxed grey bars represent on-shift periods. Unshaded crosses represent practice neurobehavioural test bouts and shaded crosses represent analysed neurobehavioural test bouts. All conditions undertook two baseline nights with 10h TIB sleep opportunities, four 24h periods on a Fixed A, Fixed B or Rotating shift schedule with 20h TIB per 48h, and two days back on a day schedule with 10h TIB ‘recovery sleep’ opportunities.

Figure 2.

Mean ± SEM per 4 8-hour period for sleep variables – total sleep time (TST), wake after sleep onset (WASO), sleep efficiency (SE), N1, N2, N3 and rapid eye movement (R). Grey bars display the Fixed A group, white bars display Fixed B and black bars are the Rotating group. Asterisks represent statistically significant differences between conditions, and asterisks with brackets represent statistically significant differences between 4 8-hour periods to BL and/or RTDS (p<0.05).
Mean ± SEM per 4 8-hour period for sleep variables – total sleep time (TST), wake after sleep onset (WASO), sleep efficiency (SE), N1, N2, N3 and rapid eye movement (R). Grey bars display the Fixed A group, white bars display Fixed B and black bars are the Rotating group. Asterisks represent statistically significant differences between conditions, and asterisks with brackets represent statistically significant differences between 4 8-hour periods to BL and/or RTDS (p<0.05).

Figure 3.

Mean ± SEM for sleep latencies during baseline and return to daytime schedule (RTDS) 4 8h periods – sleep onset latency (SOL), N2, N3 and rapid eye movement (R) latencies. Grey bars display the Fixed A group, white bars display Fixed B and black bars are the Rotating group. Asterisks represent statistically significant differences between conditions, and asterisks with brackets represent statistically significant differences between 4 8-hour periods to BL and/or RTDS (p<0.05).
Mean ± SEM for sleep latencies during baseline and return to daytime schedule (RTDS) 4 8h periods – sleep onset latency (SOL), N2, N3 and rapid eye movement (R) latencies. Grey bars display the Fixed A group, white bars display Fixed B and black bars are the Rotating group. Asterisks represent statistically significant differences between conditions, and asterisks with brackets represent statistically significant differences between 4 8-hour periods to BL and/or RTDS (p<0.05).

Figure 4.

Mean ± SEM per 48-hour period for waking function – Psychomotor Vigilance Task (PVT) Lapses, Karolinska Sleepiness Scale (KSS) and positive and negative affect. Grey bars display the Fixed A group, white bars display Fixed B and black bars are the Rotating group. Asterisks represent statistically significant differences between conditions, and asterisks with brackets represent statistically significant differences between 4 8-hour periods to BL and/or RTDS (p<0.05).
Mean ± SEM per 48-hour period for waking function – Psychomotor Vigilance Task (PVT) Lapses, Karolinska Sleepiness Scale (KSS) and positive and negative affect. Grey bars display the Fixed A group, white bars display Fixed B and black bars are the Rotating group. Asterisks represent statistically significant differences between conditions, and asterisks with brackets represent statistically significant differences between 4 8-hour periods to BL and/or RTDS (p<0.05).

Linear mixed model analyses for performance, subjective sleepiness and mood variables summed into 4 8h periods (BL, SS1, SS2, RTDS)_

F-valuedfp
PVT Lapses
Condition2.002, 210.160
4 8h Period1.013, 630.392
Condition x 4 8h Period0.536, 630.783
PVT Median Response Time
Condition0.932, 210.410
4 8h Period1.823, 630.152
Condition x 4 8h Period0.336, 630.919
KSS
Condition0.742, 210.491
4 8h Period10.903, 63<0.001*
Condition x 4 8h Period0.806, 630.572
Positive Affect
Condition6.282, 210.007*
4 8h Period6.443, 630.001*
Condition x 4 8h Period0.446, 630.847
Negative Affect
Condition0.172, 210.841
4 8h Period6.203, 63<0.001*
Condition x4 8h Period0.936, 630.476

Linear mixed model analyses for sleep variables summed into 4 8h periods (BL, SS1, SS2, RTDS)_

F-valuedfp
TST (Hours)
Condition3.202, 200.062
4 8h Period37.023, 60<0.001*
Condition x 4 8h Period2.756, 600.020*
WASO (Mins)
Condition5.972, 200.009*
4 8h Period31.273, 60<0.001*
Condition x 4 8h Period2.496, 600.032*
Sleep Efficiency (%)
Condition3.512, 200.049*
4 8h Period38.943, 60<0.001*
Condition x 4 8h Period2.496, 600.032*
N1 (Mins)
Condition0.192, 200.832
4 8h Period0.393, 600.764
Condition x 4 8h Period1.286, 600.278
N2 (Mins)
Condition5.862, 200.010*
4 8h Period34.383, 60<0.001*
Condition x 4 8h Period2.496, 600.032*
N3 (Mins)
Condition0.232, 200.795
4 8h Period5.293, 600.003*
Condition x 4 8h Period4.016, 600.002*
Stage R (Mins)
Condition0.062, 200.936
4 8h Period31.473, 60<0.001*
Condition x 4 8h Period0.346, 600.913

Linear mixed model analyses for sleep onset latencies averaged into 4 8h periods for time-matched sleep opportunities (BL, RTDS)_

F-valuedfp
Sleep Onset Latency
Condition1.882, 200.179
4 8h Period7.451, 200.013*
Condition x 4 8h Period1.652, 200.217
N2 Latency
Condition1.852, 200.184
4 8h Period7.591, 200.013*
Condition x 4 8h Period2.132, 200.145
N3 Latency
Condition1.242, 200.310
4 8h Period5.081, 200.036*
Condition x 4 8h Period2.872, 200.080
Stage R Latency
Condition0.652, 200.532
4 8h Period0.721, 200.407
Condition x 4 8h Period2.382, 200.118
DOI: https://doi.org/10.21913/JDRSSesw.v1i1.1224 | Journal eISSN: 2206-5369 | Journal ISSN: 2205-0612
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Language: English
Page range: 39 - 56
Published on: Sep 30, 2022
Published by: University of South Australia
In partnership with: Paradigm Publishing Services
Publication frequency: 1 issue per year
Keywords:
cognitive performance,
mood,
recovery,
shift work,
split shifts
Related subjects:
Social sciences,
Education,
Education, other,
Social pedagogy, social work

© 2022 S Centofanti, M Short, CJ Hilditch, J Dorrian, M Kohler, S Banks, published by University of South Australia
This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 License.

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