Table 3.
Comparison of Actigraph GT3X measured sleep outcomes to PSG and comparison of wrist and hip positioned devices.
| Sleep variable | Tool | Placement | n | Mean (SD) | Mean ∆ (95% CI) Act-PSG | P PSG-Act | P Hip vs wrist |
|---|---|---|---|---|---|---|---|
| Sleep onset (hh:min) | PSG | PSG | 23 | 20:37 (0:38) | |||
| Actigraph GT3X | Hip | 23 | 20:44 (0:43) | 0:06 (−7, 20) | .328 | ||
| Wrist | 23 | 20:58 (0:33) | 0:21 (13, 31) | <.001 | .022 | ||
| Sleep offset (hh:min) | PSG | 23 | 6:50 (0:38) | ||||
| Actigraph GT3X | Hip | 23 | 6:49 (0:43) | 0:00 (−11, 11) | .898 | ||
| Wrist | 23 | 6:45 (0:39) | −0:05 (−11, 1) | .086 | .357 | ||
| SPT iii (min) | PSG | 23 | 613 (43) | ||||
| Actigraph GT3X | Hip | 23 | 606 (40) | −7 (−22, 7) | .296 | ||
| Wrist | 23 | 586 (34) | −27 (−37, −16) | <.001 | .004 | ||
| WASO iv median (IQR) | PSG | 23 | 48 (19) | ||||
| (min) | Actigraph GT3X | Hip | 23 | 12 (0, 41) | −34 (−14 to −9) | <.001 | |
| Wrist | 23 | 48 (10, 78) | −7 (−36 to 19) | .784 | .001 | ||
| Sleep efficiency v (%) | PSG | 23 | 92.2 (91 to 93) | ||||
| Median (IQR) | Actigraph GT3X | Hip | 23 | 98.0 (93 to 100) | 5.8 (1.8 to 7.2) | <.001 | |
| Wrist | 23 | 92.5 (86.5 to 98.1) | 1.3 (−4.2 to 5.6) | .717 | .001 | ||
| Total sleep time vi (min) | PSG | 23 | 563 (46) | ||||
| Actigraph GT3X | Hip | 23 | 584 (64) | 21 (1, 41) | .043 | ||
| Wrist | 23 | 538 (64) | −26 (−49, −3) | .027 | <.001 |
iComparison to PSG using paired t-tests (WASO compared using Wilcoxon rank sum test).
iiComparison of hip and wrist measured sleep outcomes using paired t-tests (WASO compared using Wilcoxon rank sum test).
Wilcoxon Rank Sum tests used to compare actigraphy to PSG.
iii
SPT is the time between sleep onset and offset.
iv
WASO is the minutes of wake between sleep onset and sleep offset.
v
Sleep efficiency = [(total sleep time−WASO)/sleep duration]×100.
vi
Total sleep time is the time between sleep onset and offset with WASO removed.
Bolded text indicates p < 0.05.