Table 1. Demographic Variables and PSQI Scores.
| Variable | Mean (SE) | t 142 a | P value | |
|---|---|---|---|---|
| Forward rotating shift (n = 80) | Backward rotating shift (n = 64) | |||
| Age, y | 40.4 (1.0) | 42.3 (1.3) | −0.89 | .37 |
| Time on the job, y | 14.9 (0.9) | 15.8 (1.4) | 0.93 | .35 |
| PSQI subscale score | ||||
| Sleep duration | 1.16 (0.07) | 1.31 (0.09) | −1.22 | .22 |
| Sleep disturbance | 1.35 (0.11) | 1.17 (0.11) | 0.91 | .36 |
| Sleep latency | 1.11 (0.09) | 0.94 (0.11) | 1.34 | .18 |
| Daytime dysfunction | 0.50 (0.10) | 0.44 (0.09) | 0.11 | .91 |
| Sleep efficiency | 1.24 (0.06) | 1.12 (0.06) | 1.45 | .15 |
| Sleep quality | 0.16 (0.07) | 0.11 (0.07) | 0.60 | .55 |
| Medication to sleep | 1.00 (0.09) | 1.12 (0.10) | −0.94 | .35 |
| Total score | 6.54 (0.35) | 6.22 (0.36) | 0.80 | .42 |
Abbreviation: PSQI, Pittsburgh Sleep Quality Index.
a
Data are the results of the t tests comparing the means log(1 + x) values of the 2 groups.