Table 2. Summary of Generalized Estimated Equation Analysis.
| Measurement | Mean (SD) | P valuea | ||||
|---|---|---|---|---|---|---|
| Baseline | Postintervention | Follow-up | Interaction effect | Group effect | Time effect | |
| Primary outcomes (actigraphy-assessed) | ||||||
| Sleep efficiency, % | ||||||
| Control | 80.8 (10.2) | 79.5 (9.6) | 77.2 (9.5) | <.001 | .03 | <.001 |
| Exercise | 82.6 (7.5) | 84.5 (5.7) | 82.5 (8.8) | |||
| Tai chi | 82.4 (8.1) | 84.2 (6.2) | 84.9 (7.1) | |||
| Wake time after sleep onset, min | ||||||
| Control | 82.1 (51.2) | 89.7 (48.4) | 100.1 (55.3) | <.001 | .02 | .001 |
| Exercise | 79.0 (37.8) | 68.4 (30.5) | 70.3 (28.9) | |||
| Tai chi | 76.6 (36.3) | 70.8 (37.0) | 65.5 (33.5) | |||
| No. of awakenings | ||||||
| Control | 17.5 (6.5) | 17.8 (6.8) | 18.9 (6.7) | <.001 | .01 | .01 |
| Exercise | 18.8 (7.0) | 15.7 (7.1) | 17.3 (6.5) | |||
| Tai chi | 19.0 (7.1) | 16.4 (6.3) | 16.6 (6.8) | |||
| Sleep onset latency, min | ||||||
| Control | 7.2 (7.1) | 8.8 (8.0) | 9.9 (9.0) | .006 | .28 | .003 |
| Exercise | 5.6 (8.3) | 7.3 (7.8) | 6.3 (8.5) | |||
| Tai chi | 5.7 (5.5) | 6.2 (5.3) | 5.0 (4.9) | |||
| Total sleep time, min | ||||||
| Control | 372.5 (77.5) | 380.5 (78.7) | 357.3 (74.8) | .71 | .58 | .30 |
| Exercise | 388.5 (66.7) | 401.3 (62.2) | 387.4 (62.9) | |||
| Tai chi | 396.4 (69.9) | 404.5 (69.5) | 382.4 (67.3) | |||
| Average awaken time, min | ||||||
| Control | 4.9 (3.4) | 5.5 (3.0) | 5.4 (2.6) | .44 | .20 | .62 |
| Exercise | 4.8 (5.3) | 5.1 (3.2) | 4.4 (2.2) | |||
| Tai chi | 4.1 (1.6) | 4.8 (3.3) | 5.2 (7.8) | |||
| Secondary outcomes | ||||||
| PSQI | ||||||
| Control | 11.4 (3.2) | 10.9 (3.5) | 10.0 (3.8) | .004 | .72 | .21 |
| Exercise | 11.4 (2.9) | 9.7 (3.8) | 8.9 (4.0) | |||
| Tai chi | 11.3 (2.9) | 7.9 (3.8) | 8.2 (3.8) | |||
| ISI | ||||||
| Control | 13.7 (5.2) | 12.9 (5.6) | 11.3 (5.2) | <.001 | .24 | .11 |
| Exercise | 13.4 (5.1) | 10.6 (5.8) | 9.1 (5.3) | |||
| Tai chi | 14.0 (4.0) | 9.1 (5.1) | 8.9 (5.6) | |||
| Sleep efficiency in 7-d sleep diary, %b | ||||||
| Control | 66.9 (32.5) | 66.9 (20.4) | 72.0 (18.1) | <.001 | .049 | .95 |
| Exercise | 62.7 (18.0) | 67.1 (17.6) | 78.2 (13.6) | |||
| Tai chi | 64.3 (18.4) | 74.0 (19.2) | 80.4 (16.6) | |||
| Wake time after sleep onset in 7-d sleep diary, minb | ||||||
| Control | 89.8 (88.8) | 84.2 (84.0) | 66.2 (69.3) | .02 | .50 | .24 |
| Exercise | 99.3 (82.2) | 80.3 (78.6) | 49.4 (51.9) | |||
| Tai chi | 94.8 (76.5) | 48.0 (56.3) | 46.3 (59.1) | |||
| Total sleep time in 7-d sleep diary, minb | ||||||
| Control | 269.6 (94.3) | 284.0 (97.2) | 293.0 (91.3) | .01 | .49 | .46 |
| Exercise | 262.7 (78.1) | 290.7 (88.7) | 326.4 (80.9) | |||
| Tai chi | 275.0 (98.2) | 336.1 (101.2) | 332.3 (91.2) | |||
| No. of awakenings in 7-d sleep diaryb | ||||||
| Control | 1.9 (1.3) | 1.7 (1.2) | 1.6 (1.1) | .07 | .18 | .61 |
| Exercise | 2.1 (1.4) | 2.0 (1.3) | 1.7 (1.1) | |||
| Tai chi | 2.1 (1.2) | 1.6 (1.2) | 1.5 (1.2) | |||
| Sleep onset latency in 7-d sleep diary, minb | ||||||
| Control | 66.9 (65.7) | 70.9 (71.3) | 50.2 (49.3) | .12 | .98 | .21 |
| Exercise | 66.8 (52.2) | 62.4 (51.2) | 44.2 (31.3) | |||
| Tai chi | 63.5 (48.8) | 46.1 (49.2) | 38.0 (41.5) | |||
| Average awaken time in 7-d sleep diary, minb | ||||||
| Control | 57.5 (64.8) | 60.3 (76.7) | 43.1 (51.9) | .22 | .68 | .10 |
| Exercise | 63.6 (76.1) | 51.0 (70.2) | 31.1 (34.3) | |||
| Tai chi | 55.2 (62.4) | 28.4 (41.1) | 29.2 (40.6) | |||
| Hypnotic medication usage recorded in 7-d sleep diary, LRD units/wk | ||||||
| Control (n = 24) | 8.5 (7.7) | 8.5 (7.6) | 8.6 (7.8) | <.001 | .05 | .04 |
| Exercise (n = 17) | 8.1 (5.2) | 6.5 (6.4) | 5.9 (7.2) | |||
| Tai chi (n = 19) | 7.7 (6.6) | 2.9 (6.1) | 3.1 (5.9) | |||
Abbreviations: ISI, insomnia severity index; LRD, lowest recommended dosage; PSQI, Pittsburgh sleep quality index.
a
Generalized estimated equation model, with baseline measurement as the covariate, was used to analyze the data.
b
Mean values across 7-day sleep diary.