Table 2.
Participants’ response to Pittsburgh sleep quality index (PSQI) and reliability of the scale (n=958).
| Content | Component score (N=958) | Cronbach’s α coefficient1 | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| 0 | 1 | 2 | 3 | Missing ratio | Mean ± SD | Median (Q25, Q75) | Total sample N=958 | Training set N=479 | Validation set N=479 | |
| Component 1 sleep quality | 28 (2.92%) | 277 (28.91) | 528 (55.11) | 125 (13.05%) | 0 | 1.78 ± 0.70 | 2 (1,2) | 0.561 | 0.575 | 0.544 |
| Component 2 sleep latency | 171 (17.85%) | 145 (15.14) | 404 (41.46%) | 241 (25.16%) | 22 (2.3%) | 1.74 ± 1.03 | 2 (1,3) | 0.608 | 0.609 | 0.605 |
| Component 3 sleep duration | 675 (70.46%) | 175 (18.27%) | 58 (6.05%) | 50 (5.22%) | 2 (0.2%) | 0.46 ± 0.83 | 0 (0,1) | 0.577 | 0.586 | 0.567 |
| Component 4 sleep efficiency | 212 (22.13%) | 276 (28.81%) | 233 (24.32%) | 237 (24.74%) | 11 (1.1) | 1.52 ± 1.09 | 1 (1,2) | 0.624 | 0.641 | 0.605 |
| Component 5 sleep disturbance | 77 (8.04%) | 291 (30.38%) | 328 (34.24%) | 262 (27.35%) | 4 (0.4%) | 1.81 ± 0.93 | 2 (1,3) | 0.632 | 0.641 | 0.623 |
| Component 6 medication use | 934 (97.50%) | 5 (0.52%) | 3 (0.31%) | 16 (1.67%) | 40 (4.2%) | 0.06 ± 0.41 | 0 (0,0) | 0.724 | 0.737 | 0.711 |
| Component 7 daytime dysfunction | 321 (33.51%) | 301 (31.42%) | 287 (29.95%) | 49 (5.12%) | 8 (0.8%) | 1.07 ± 0.91 | 1 (0,2) | 0.694 | 0.705 | 0.683 |
| PSQI-7 | 8.44 ± 3.09 | 8 (6,10) | 0.675 | 0.685 | 0.663 | |||||
| PSQI-5 (delete component 6 and 7) | 7.31 ± 2.88 | 7 (5,9) | 0.778 | 0.781 | 0.775 | |||||
1Cronbach’s α coefficient of the scale when each item was deleted.