Table 4. Effects of LT on Actigraphy-Derived Sleep and Wake Metrics.
| Actigraphy Marker | Mean (SD) |
P Value, Group/ Condition/ Interaction |
||||||
|---|---|---|---|---|---|---|---|---|
| Baseline | Postintervention (Week 4) |
P Value, Group/ Condition/ Interaction |
Postwashout (Week 6) | |||||
| Bright LT | Dim-Red LT | Bright LT | Dim-Red LT | Bright LT | Dim-Red LT | |||
| Sleep Period | ||||||||
| Sleep onset latency, min | 30.16 (36.05) |
23.54 (21.45) |
27.68 (22.43) |
17.06 (13.04) |
.43/.75/.03 | 20.82 (10.67) |
16.88 (9.75) |
.36/.73/.03 |
| Total activity counts | 7247.5 (7242.5) |
8538.3 (9560.7) |
8680.9 (7807.1) |
7898.9 (4750.0) |
.54/.002 | 8755.8 (7445.1) |
7012.7 (4456.9) |
.79/.61 |
| Average activity counts | 19.74 (15.21) |
22.31 (18.58) |
24.09 (20.05) |
21.17 (11.91) |
.65/.002 | 22.22 (14.86) |
18.02 (11.38) |
.93/.73 |
| Sleep efficiency | 74.85 (15.41) |
75.94 (15.26) |
74.65 (16.23) |
79.32 (9.02) |
.60/.23 | 76.64 (10.43) |
81.06 (9.61) |
.39/.06 |
| Wake after sleep onset, min | 38.53 (40.67) |
43.21 (34.64) |
44.31 (42.52) |
43.37 (22.78) |
.37/<.001 | 48.06 (43.07) |
40.58 (28.02) |
.71/.45/.003 |
| Sleep time, min | 310.05 (72.49) |
327.49 (87.11) |
310.92 (82.14) |
322.35 (66.48) |
.49/.33 | 317.78 (51.63) |
334.32 (58.79) |
.49/.05 |
| Average light/illuminance, lux | 4.13 (8.35) |
1.46 (2.40) |
10.41 (32.89) |
7.47 (25.30) |
.04/.21 | 1.43 (2.09) |
0.75 (0.94) |
.02/.03 |
| Maximum light/highest illuminance, lux | 51.30 (41.39) |
39.89 (56.95) |
87.71 (180.37) |
26.66 (27.84) |
.24/.11/.02 | 34.57 (33.53) |
16.71 (13.91) |
.008/.26 |
| Wake Period | ||||||||
| Total activity counts | 164 847 (71 139) |
180 818 (64 901) |
189 413 (88 824) |
189 676 (47 246) |
.59/<.001 | 170 951 (90 948) |
184 419 (47 372) |
.49/.01 |
| Average activity counts | 165.01 (66.87) |
185.15 (56.63) |
194.59 (87.81) |
194.09 (47.35) |
.39/<.001/.02 | 173.70 (89.08) |
183.97 (43.43) |
.51/.007 |
| Sleep time, min | 385.72 (145.76) |
290.78 (82.84) |
344.09 (103.68) |
302.19 (109.43) |
.06/.24 | 340.53 (114.14) |
345.29 (136.13) |
.45/.69 |
| % Scored total sleep time | 38.85 (14.58) |
32.18 (10.16) |
34.99 (10.61) |
30.12 (9.80) |
.12/<.001 | 37.61 (13.56) |
32.29 (9.78) |
.15/.07 |
| Average light/illuminance, lux | 507.42 (445.48) |
304.74 (337.10) |
706.49 (717.92) |
314.82 (505.38) |
.01/<.001/.002 | 569.81 (511.67) |
236.20 (234.39) |
.00/<.001 |
| Maximum light/highest illuminance, lux | 23 870 (13 716) |
14 539 (13 134) |
24 509 (13 189) |
13 291 (17 333) |
.004/.001 | 23 637 (14 272) |
14 451 (12 564) |
.008/.004/.03 |
Abbreviation: LT, light therapy.