Table 3.
Random-effects model of the relationships between shift schedule characteristics with fatigue and sleep quality (scale 0 –10; higher score indicating more fatigue and poorer sleep quality). Boldface indicates statistical significance (P<0.05).[CI=confidence interval.]
| Fatigue | Sleep quality | |||
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|
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|---|---|---|---|---|
| Univariate model a | Multivariate model b | Univariate model a | Multivariate model b | |
|
|
|
|
|
|
| B (95% CI) | B (95% CI) | B (95% CI) | B (95% CI) | |
| Type of shift c | ||||
| Morning | 0.13 (-0.28–0.55) | 0.13 (-0.28–0.54) | 0.28 (-0.14–0.70) | 0.28 (-0.14–0.70) |
| Day | Ref. | Ref. | Ref. | Ref. |
| Evening | -0.07 (-0.32–0.17) | -0.08 (-0.32–0.17) | 0.10 (-0.14–0.34) | 0.09 (-0.15–0.34) |
| Night shift | 0.22 (0.05–0.39) | 0.22 (0.05–0.39) | 0.64 (0.47–0.80) | 0.64 (0.47–0.80) |
| Day off following workday | 0.51 (0.34–0.68) | 0.51 (0.34–0.68) | 0.10 (-0.07–0.27) | 0.10 (-0.07–0.27) |
| ≥2 days off following a working day | -0.45 (-0.62– -0.29) | -0.46 (-0.62– -0.29) | -0.06 (-0.22–0.10) | -0.06 (-0.22–0.10) |
| Time between shifts (hours rest) | ||||
| >16 | Ref. | Ref. | Ref. | Ref. |
| 11–16 | 0.40 (0.23–0.57) | 0.43 (0.26–0.61) | -0.07 (-0.24–0.10) | 0.01 (-0.18–0.16) |
| <11 (quick return) | 1.64 (1.28–2.00) | 1.94 (1. 57–1.2.31) | -0.28 (-0.64–0.10) | 0.15 (-0.23–0.53) |
| Rotation direction | ||||
| Forward | Ref. | Ref. | Ref. | Ref. |
| Stable | 0.20 (-0.01–0.41) | 0.22 (0.01–0.43) | -0.16 (-0.35–0.02) | -0.04 (-0.23–0.14) |
| Backward | 0.33 (0.09–0.57) | 0.49 (0.23–0.74) | -0.32 (-0.54– -0.08) | 0.12 (-0.13–0.37) |
| Successive night shifts | ||||
| 0 | Ref. | Ref. | Ref. | Ref. |
| 1 | -0.01 (-0.16–0.13) | -0.01 (-0.15–0.14) | 0.69 (0.55–0.82) | 0.69 (0.55–0.82) |
| 2 | 0.68 (0.49–0.87) | 0.69 (0.49–0.88) | 0.55 (0.36–0.74) | 0.56 (0.37–0.74) |
| 3 | 0.45 (0.12–0.79) | 0.56 (0.13–0.79) | 0.47 (0.16–0.78) | 0.47 (0.16–0.78) |
| ≥4 | 0.58 (0.16–0.99) | 0.58 (0.16–0.99) | 0.26 (-0.15–0.67) | 0.27 (-0.14–0.67) |
Unadjusted model per roster characteristic.
Model per roster characteristic adjusted for age, gender, education, children living at home under the age of 12, general health, and chronotype. Time between shifts and rotation direction additionally adjusted for type of shift.
Morning shift (starts after 06:00 and before 11:00 and mostly at 07:00 hours); day shift (starts after 11:00 and before 14:00 hours); evening shift (starts after 14:00 and ends before 01:00 hours); night shift (starts after 14:00 and ends after 01:00 hours).