Characteristics of all the participants and classified according to self-reported sleep quality
| All participants | Sleep quality | P value | |||
| Very good (n=103) | Good (n=441) | Poor (n=166) | |||
| Age mean, years (SD) | 49.0 (9.7) | 47.5 (10.6) | 49.1 (9.7) | 49.8 (9.2) | 0.072 |
| Gender, n (%) | 0.10 | ||||
| Female | 631 (88.9) | 85 (13.5) | 397 (62.9) | 149 (23.6) | |
| Male | 79 (11.1) | 18 (22.8) | 44 (55.7) | 17 (21.5) | |
| Education, n (%) | 0.36 | ||||
| Vocational school | 21 (3) | 4 (19.1) | 14 (66.7) | 3 (14.3) | |
| College-level | 361 (51.6) | 53 (14.7) | 232 (64.3) | 76 (21.1) | |
| University-level | 318 (45.4) | 45 (14.2) | 188 (59.1) | 85 (26.7) | |
| Cohabiting, n (%) | 0.64 | ||||
| Yes | 575 (81.2) | 83 (14.4) | 353 (61.4) | 139 (24.2) | |
| No | 133 (18.8) | 20 (15.0) | 86 (64.7) | 27 (20.3) | |
| 3-shift work, n (%) | 0.41 | ||||
| Yes | 76 (10.9) | 15 (19.7) | 44 (57.9) | 17 22.4) | |
| No | 620 (89.1) | 87 (14.0) | 386 (62.3) | 147 (23.7) | |
| Smoking, n (%) | 0.45 | ||||
| Yes | 64 (9.0) | 9 (14.1) | 44 (68.8) | 11 (17.2) | |
| No | 645 (91.0) | 94 (14.6) | 396 (61.4) | 155 (24.0) | |
| Harmful alcohol consumption, n (%) | 0.55 | ||||
| Yes | 101 (14.2) | 18 (17.8) | 59 (58.4) | 24 (23.8) | |
| No | 609 (85.8) | 85 (14.0) | 382 (62.7) | 142 (23.3) | |
| Body mass index mean (95% CI) | 26.8 (26.42 to 27.13) | 26.4 (25.50 to 27.25) | 27.0 (26.54 to 27.46) | 26.5 (25.72 to 27.24) | 0.92 |
| Disease burden*, n (%) | 0.0016 | ||||
| Yes | 468 (65.9) | 55 (11.8) | 289 (61.8) | 124 (26.5) | |
| No | 242 (34.1) | 48 (19.8) | 152 (62.8) | 42 (17.4) | |
| Depression (MDI), n (%) | 0.016 | ||||
| Yes | 9 (1.3) | 0 (0.0) | 3 (33.3) | 6 (66.7) | |
| No | 701 (98.7) | 103 (14.7) | 438 (62.5) | 160 (22.8) | |
| MDI mean score (95% CI) | 5.0 (4.57 to 5.43) | 2.4 (1.75 to 2.97) | 4.1 (3.59 to 4.51) | 9.2 (8.09 to 10.27) | <0.0001 |
| Level of anxiety (GAD-7), n (%) | <0.0001 | ||||
| No anxiety | 534 (75.2) | 92 (17.2) | 343 (64.2) | 99 (18.5) | |
| Mild anxiety | 143 (20.1) | 10 (7.0) | 85 (59.4) | 48 (33.6) | |
| Moderate anxiety | 26 (3.7) | 1 (3.9) | 10 (38.5) | 15 (57.7) | |
| Severe anxiety | 7 (1.0) | 0 (0.0) | 3 (42.9) | 4 (57.1) | |
| BBI15 mean total score (95% CI) | 31.6 (30.82 to 32.41) | 28.3 (26.43 to 30.23) | 31.0 (30.05 to 31.99) | 35.4 (33.60 to 37.20) | <0.0001 |
| Occupational stress (BBI15), n (%) | <0.0001 | ||||
| No stress | 592 (89.4) | 97 (16.4) | 374 (63.2) | 121 (20.4) | |
| Stress | 70 (10.6) | 3 (4.3) | 38 (54.3) | 29 (41.4) | |
| Sleep duration mean (95% CI) | 7.00 (6.93 to 7.07) | 7.50 (7.35 to 7.66) | 7.17 (7.09 to 7.24) | 6.23 (6.09 to to 6.38) | <0.0001 |
| EUROHIS mean score (95% CI) | 4.07 (4.03 to 4.11) | 4.38 (4.30 to 4.45) | 4.09 (4.05 to 4.14) | 3.83 (3.75 to 3.91) | <0.0001 |
| WAS mean score (95% CI) | 8.31 (8.21 to 8.41) | 8.99 (8.78 to 9.20) | 8.34 (8.22 to 8.46) | 7.80 (7.55 to 8.04) | <0.0001 |
| Level of work ability (WAS), n (%) | <0.0001 | ||||
| Poor | 27 (3.8) | 1 (3.7) | 12 (44.4) | 14 (51.9) | |
| Moderate | 114 (16.1) | 3 (2.6) | 69 (60.5) | 42 (36.8) | |
| Good | 459 (64.9) | 61 (13.3) | 298 (64.9) | 100 (21.8) | |
| Excellent | 107 (15.2) | 37 (34.6) | 60 (56.1) | 10 (9.4) | |
*At least one chronic disease diagnosed by a physician.
BBI15, Bergen Burnout Indicator 15; EUROHIS, EUROHIS QOL 8-item index; GAD-7, General Anxiety Disorder 7-item Scale; MDI, Major Depression Inventory; WAS, Work Ability Score.