Table 3.
Within-Subject Comparisons Between Self-Report Pittsburgh Sleep Quality Index and Actigraphy (n = 71)
| Sleep characteristic | Mean ± SD | Pearson correlation (r) with PSQI | Paired t statistic (p value) | Cohen's d |
|---|---|---|---|---|
| Time in bed (hours) | ||||
| PSQI | 7.5 ± 1.1 | |||
| Actigraphy | 7.9 ± 1.1 | 0.44a | 2.6 (0.01) | 0.439 |
| Recline/sleep weekdays | 7.3 ± 1.3 | 0.54a | 1.3 (0.21)b | 0.219 |
| Recline/sleep weekends | 8.0 ± 1.4 | 0.34a | 2.9 (0.004) | 0.490 |
| SOL (minutes) | ||||
| PSQI | 19.3 ± 16.9 | |||
| Actigraphy | 11.7 ± 7.8 | 0.24 | 3.5 (0.001) | 0.591 |
| Sleep duration (hours) | ||||
| PSQI | 6.7 ± 1.1 | |||
| Actigraphy | 7.0 ± 1.2 | 0.40a | 2.3 (0.028) | 0.388 |
| Sleep efficiency (%) | ||||
| PSQI | 89.7 ± 11.8 | |||
| Actigraphy | 89.2 ± 9.1 | 0.05 | 0.3 (0.81)b | 0.050 |
a
Pearson correlation p-value ≤0.05; measure significantly correlated with PSQI measure.
b
Paired samples t-test p-value >0.05; measure not significantly different from PSQI measure.
SOL, sleep onset latency.