Table 3.
Light therapy characteristics *.
| Characteristic | No. (%) a | p | N | |||
|---|---|---|---|---|---|---|
| All Survivors | BWL (n = 83) | DWL (n = 83) | ||||
| Season LT start | 0.94 | 164 | ||||
| Autumn | 42 (25.6) | 23 (27.7) | 19 (23.5) | |||
| Winter | 47 (28.7) | 23 (27.7) | 24 (29.6) | |||
| Spring | 47 (28.7) | 23 (27.7) | 24 (29.6) | |||
| Summer | 28 (17.1) | 14 (16.9) | 14 (17.3) | |||
| LT device | ||||||
| Litebook Edge | 37 (22.6) | 18 (21.7) | 19 (23.5) | 164 | ||
| Luminette | 127 (77.4) | 65 (78.3) | 62 (76.5) | 164 | ||
| Days of LT use based on LT diary b | 0.52 | 155 | ||||
| Mean | 22.7 | 22.5 | 22.9 | |||
| SD | 4.4 | 4.6 | 4.0 | |||
| >25 days c | 3 (1.9) | 0 (0.0) | 3 (3.9) | 0.13 | 155 | |
| 25 days | 58 (37.4) | 33 (41.8) | 25 (32.9) | |||
| 14–24 days | 87 (56.1) | 41 (51.9) | 46 (60.5) | |||
| 1–13 days (premature stop) | 7 (4.5) | 5 (6.3) | 2 (2.6) | |||
| Time difference sleep end and LT start (min) d | 0.13 | 155 | ||||
| Mean | 25.0 | 27.4 | 22.6 | |||
| SD | 19.5 | 22.6 | 15.3 | |||
| Time difference DLMO and LT start (h) | 0.17 | 45 | ||||
| Mean | 11.4 | 11.1 | 11.7 | |||
| SD | 1.5 | 1.0 | 1.9 | |||
| n | 45 | 23 | 22 | |||
| Self-reported side effects | ||||||
| Headache/nausea | 35 (21.6) | 21 (25.6) | 14 (17.5) | 0.21 | 162 | |
| Feeling agitated b | 5 (3.1) | 1 (1.2) | 4 (5.0) | 0.21 | 162 | |
| Tired eyes | 30 (18.5) | 11 (13.4) | 19 (23.8) | 0.09 | 162 | |
| Change in vision b | 8 (4.9) | 5 (6.1) | 3 (3.8) | 0.72 | 162 | |
| Other self-reported side effects e | 15 (9.3) | 6 (7.3) | 9 (11.3) | 0.39 | 162 | |
| Premature stop of LT | 13 (7.8) | 7 (8.4) | 6 (7.2) | 0.77 | 166 | |
| Reasons for premature stop b | 0.21 | 13 | ||||
| Self-reported side effects | 7 (53.8) | 5 (71.4) | 2 (33.3) | |||
| No time or personal circumstances | 6 (46.2) | 2 (28.6) | 4 (66.7) | |||
Note: shading in the table represents the distinction between variables. * Two participants never started with light therapy and therefore characteristics of light therapy are reported for 164 participants. Light therapy diaries were completed by 155 participants. DLMO was determined for 45 participants. In total, 162 participants completed the screening on side effects during a telephone call. Abbreviations: BWL, bright white light; DLMO, dim light melatonin onset; DWL, dim white light; LT, light therapy. a Unless otherwise specified. b Categorical test results is based on Fisher’s Exact Test. c Some individuals misinterpreted the study protocol and used light therapy for 28, 30, or 33 days. d Based on Mann–Whitney Test. e Other self-reported side effects included worse sleep quality (n = 7), feeling more fatigued (n = 2), feeling rushed (n = 1), shingles (n = 1), feeling confused (n = 1), sensitive gingiva (n = 1), and a dry mouth (n = 1).