Table 2.
Baseline characteristics of the participants.
| Characteristics | CBTa group (N=120) | Control group (N=120) | Total (N=240) | P value | |
| Gender | .74 | ||||
| Male, n (%) | 39 (32.5) | 56 (46.7) | 95 (38.9) | ||
| Female, n (%) | 81 (67.5) | 64 (53.3) | 145 (41.2) | ||
| Age in years, mean (SD) | 29.9 (4.3) | 30.5 (6.0) | 30.3 (5.3) | .43 | |
| Monthly mean overtime hours, n (%) | .85 | ||||
| Almost none | 2 (1.8) | 1 (1.1) | 3 (1.5) | ||
| Less than 40 hours | 25 (22.3) | 19 (20.2) | 44 (21.4) | ||
| 40-79 hours | 66 (58.9) | 54 (57.4) | 120 (58.3) | ||
| 80 hours or more | 19 (17.0) | 20 (21.3) | 39 (18.9) | ||
| Missing | 8 (6.7) | 26 (21.7) | 34 (14.2) | ||
| Marital status, n (%) | .16 | ||||
| Unmarried | 59 (52.2) | 60 (62.5) | 119 (56.9) | ||
| Married | 54 (47.8) | 36 (37.5) | 90 (43.1) | ||
| No response | 7 (5.8) | 24 (20.0) | 31 (12.9) | ||
| Drinking habits, n (%) | .53 | ||||
| Not at all | 45 (39.8) | 30 (31.6) | 75 (36.1) | ||
| 1-3 days a week | 53 (46.9) | 48 (50.5) | 101 (48.6) | ||
| 4-6 days a week | 10 (8.8) | 13 (13.7) | 23 (11.1) | ||
| Every day | 5 (4.4) | 4 (4.2) | 9 (4.3) | ||
| No response | 7 (5.8) | 25 (20.8) | 32 (13.3) | ||
| Exercise habits, n (%) | .67 | ||||
| Not at all | 46 (40.7) | 43 (44.8) | 89 (42.6) | ||
| 1-2 days a week | 58 (51.3) | 48 (50.0) | 106 (50.7) | ||
| 3 or more days a week | 9 (8.0) | 5 (5.2) | 14 (6.7) | ||
| No response | 7 (5.8) | 24 (20.0) | 31 (12.9) | ||
| Mean weekday sleep time, n (%) | .92 | ||||
| Less than 5 hours | 10 (8.8) | 7 (7.3) | 17 (8.1) | ||
| 5-6 hours | 77 (68.1) | 66 (68.8) | 143 (68.4) | ||
| 7-8 hours | 26 (23.0) | 23 (24.0) | 49 (23.4) | ||
| 9 hours or more | 0 (0.0) | 0 (0.0) | 0 (0.0) | ||
| No response | 7 (5.8) | 24 (20.0) | 31 (12.9) | ||
| Mean weekend sleep time, n (%) | .42 | ||||
| Less than 5 hours | 2 (1.8) | 0 (0.0) | 2 (1.0) | ||
| 5-6 hours | 19 (17.0) | 16 (16.7) | 35 (16.8) | ||
| 7-8 hours | 91 (81.3) | 80 (83.3) | 171 (82.2) | ||
| 9 hours or more | 0 (0.0) | 0 (0.0) | 0 (0.0) | ||
| No response | 8 (6.7) | 24 (20.0) | 32 (13.3) | ||
| Poor mental health, n (%) | .40 | ||||
| Never sought medical advice | 100 (89.3) | 81 (84.4) | 181 (87.0) | ||
| Sought medical advice once, but not seeing a doctor currently | 11 (9.8) | 12 (12.5) | 23 (11.1) | ||
| Currently seeing a doctor regularly | 1 (0.9) | 3 (3.1) | 4 (1.9) | ||
| No response | 8 (6.7) | 24 (20.0) | 32 (13.3) | ||
| K6, mean (SD) | 3.24 (3.80) | 3.83 (4.27) | 3.51 (4.03) | .29 | |
| Tendency to perceive difficult situations as controllable, mean (SD) | 3.14 (0.85) | 3.12 (0.80) | 3.13 (0.83) | .86 | |
| Ability to perceive multiple alternative explanations, mean (SD) | 3.34 (0.84) | 3.10 (0.86) | 3.23 (0.85) | .04 | |
| Ability to generate multiple alternative solutions, mean (SD) | 3.37 (0.91) | 3.28 (0.89) | 3.33 (0.90) | .48 | |
| Subjective distress, mean (SD) | 6.03 (1.88) | 6.28 (2.14) | 6.14 (2.00) | .37 | |
aCBT: cognitive behavioral therapy.