Table 2.
Magnitude of disagreement between different measures of time in bed and total sleep time
| Measurement comparisons | Average difference (h) |
|---|---|
| Screening TIB – diary TIB* | 0.33 ± 0.49* |
| Screening TIB – actigraphic TIB* | 0.36 ± 0.61* |
| Diary TIB – actigraphic TIB | 0.03 ± 0.31 |
| Screening TST – diary TST* | 0.33 ± 0.60* |
| Screening TST – actigraphic TST* | 1.57 ± 0.82* |
| Diary TST – actigraphic TST* | 1.24 ± 0.81* |
| Screening TST – actigraphic TIB | −0.19 ± 0.63 |
| Diary TST – actigraphic TIB* | −0.52 ± 0.42* |
Indicates a significant difference between the two measurements as compared by paired t-tests (P < 0.01).
TIB, time in bed; TST, total sleep time.