Table 1.
Principal Components Analysis of PSQI Components and ESS Items1
| Component / Item | Component Number |
||||
|---|---|---|---|---|---|
| 1 | 2 | 3 | 4 | 5 | |
| PSQI Sleep Duration | — | — | 0.811 | — | — |
| PSQI Sleep Disturbances | — | 0.732 | — | — | — |
| PSQI Sleep Latency | — | 0.678 | — | — | — |
| PSQI Daytime Dysfunction | — | 0.522 | — | — | — |
| PSQI Habitual Sleep Efficiency | — | — | 0.795 | — | — |
| PSQI Sleep Quality | — | 0.608 | — | — | — |
| PSQI Medications to Sleep | — | — | — | — | 0.905 |
| ESS Item 1 (Sitting reading) | — | — | — | 0.693 | — |
| ESS Item 2 (Watching TV) | — | — | — | 0.849 | — |
| ESS Item 3 (Inactive in public) | 0.612 | — | — | — | — |
| ESS Item 4 (Car passenger) | 0.680 | — | — | — | — |
| ESS Item 5 (Lying down) | 0.636 | — | — | — | — |
| ESS Item 6 (Sitting talking) | 0.677 | — | — | — | — |
| ESS Item 7 (Sitting quietly) | 0.539 | — | — | — | — |
| ESS Item 8 (Car in traffic) | 0.714 | — | — | — | — |
1
Values shown are weightings on five rotated components (factors) from principal components analysis with eigenvalues >1.0. Only component weightings >0.5 are shown.