Table 5.
Random-effects model of the relationships between shift schedule characteristics with fatigue and sleep quality, stratified by health status (scale 0 to 10; higher score indicating poorer sleep quality). Boldface indicates statistical significance (P< 0.05). [CI=confidence interval.]
| Fatigue | Sleep quality | |||
|
|
|
|||
|---|---|---|---|---|
| Poor Health B (95% CI) a | Good health B (95% CI) a | Poor Health B (95% CI) a | Good health B (95% CI) a | |
| Type of shift b | ||||
| Morning | 0.30 (-0.61–1.20) | 0.08 (-0.38–0.55) | 0.30 (-0.58–1.18) | 0.29 (-0.19–0.77) |
| Day | Ref. | Ref. | Ref. | Ref. |
| Evening | 0.12 (-0.50–0.64) | -0.12 (-0.39–0.15) | 0.28 (-0.32–0.88) | 0.06 (-0.20–0.33) |
| Night shift | 0.38 (-0.06–0.81) | 0.20 (0.01–0.38) | 0.99 (0.59–1.39) | 0.58 (0.40–0.76) |
| Day off following workday | 0.68 (0.27–1.09) | 0.46 (0.28–0.65) | 0.11 (-0.29–0.50) | 0.10 (-0.08–0.29) |
| ≥2 days off following a working day | -0.64 (-1.02– -0.26) | -0.40 (-0.58– -0.22) | -0.20 (-0.57–0.16) | -0.00 (-0.19–0.17) |
| Time between shifts (hours rest) | ||||
| >16 | Ref. | Ref. | Ref. | Ref. |
| 11–16 | 0.21 (0.21–1.15) | 0.38 (0.20–0.57) | -0.16 (-0.63–0.31) | 0.01 (-0.17–0.18) |
| <11 (quick return) | 1.41 (1.41–3.54) | 1.84 (1.45–2.23) | 0.60 (-0.01–1.20) | -0.04 (-0.32–0.23) |
| Rotation direction | ||||
| Forward | Ref. | Ref. | Ref. | Ref. |
| Stable | 0.19 (-0.36–0.74) | 0.18 (-0.06–0.42) | -0.07 (-0.56–0.42) | -0.06 (-0.26–0.15) |
| Backward | 0.53 (-0.11–1.16) | 0.03 (-0.27–0.32) | 0.60 (-0.01–1.20) | -0.04 (-0.32–0.23) |
| Successive night shifts | ||||
| 0 | Ref. | Ref. | Ref. | Ref. |
| 1 | 0.31 (-0.07–0.69) | 0.22 (-0.001–0.45) | 1.20 (0.86–1.53) | 0.57 (0.43–0.72) |
| 2 | 0.69 (0.13–1.24) | 1.02 (0.76–1.28) | 0.84 (0.34–1.33) | 0.50 (0.29–0.70) |
| 3 | 0.83 (-0.09–1.75) | 0.73 (0.34–1.11) | .. | 0.45 (0.12–0.77) |
| ≥4 | ..c | 1.06 (0.59–1.54) | .. | 0.36 (-0.07–0.80) |
Analyses model per roster characteristics adjusted for age, gender, education, children living at home under the age of 12, chronotype, and type of shift. Successive night shifts was not 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).
Are censored due to number of observations is too low (<20) for reliable estimations.