| Participants Who Completed Only the Questionnaire (n = 309) | Participants Who Completed the Questionnaire and the Clinical Interview (n = 101) | Total Sample (N = 410) | Statistics | P Value | |
|---|---|---|---|---|---|
| Mean age, years (SD) | 47.55 (15.5) | 49.01 (14.1) | 47.91 (15.2) | t = 0.82 | .411 |
| Female sex | 184 (59.5) | 66 (65.3) | 250 (61.6) | χ2 = 0.81 | .369 |
| Marital status | χ2 = 2.39 | .496 | |||
| Married | 193 (62.5) | 56 (55.4) | 249 (60.7) | ||
| Single | 62 (20.1) | 21 (20.8) | 83 (20.2) | ||
| Separated or divorced | 33 (10.7) | 16 (15.8) | 49 (12.0) | ||
| Widowed | 14 (4.5) | 4 (4.0) | 18 (4.4) | ||
| Occupation | χ2 = 6.06 | .416 | |||
| Full-time work | 165 (53.4) | 52 (51.5) | 217 (52.9) | ||
| Part-time work | 24 (7.8) | 8 (7.9) | 32 (7.8) | ||
| Unemployed | 18 (5.8) | 5 (5.0) | 23 (5.6) | ||
| Unpaid work | 3 (1.0) | 3 (3.0) | 6 (1.5) | ||
| Retired | 63 (20.4) | 26 (25.7) | 89 (21.7) | ||
| Student | 24 (7.8) | 3 (3.0) | 27 (6.6) | ||
| Work schedule | χ2 = 1.57 | .815 | |||
| Day | 157 (50.8) | 50 (49.5) | 207 (50.5) | ||
| Evening | 7 (2.3) | 1 (1.0) | 8 (2.0) | ||
| Day and evening | 23 (7.4) | 6 (5.9) | 29 (7.1) | ||
| Night | 9 (2.9) | 4 (4.0) | 13 (3.2) | ||
| Rotating shift work | 15 (4.9) | 3 (3.0) | 18 (4.4) | ||
| Education level completed | χ2 = 4.96 | .175 | |||
| Elementary school or less | 11 (3.6) | 3 (3.0) | 14 (3.4) | ||
| High school | 122 (39.5) | 28 (27.7) | 150 (36.6) | ||
| Junior college | 75 (24.3) | 31 (30.7) | 106 (25.9) | ||
| University | 87 (28.2) | 34 (33.7) | 121 (29.5) | ||
| Insomnia Severity Index mean total score (SD) | 7.34 (6.05) | 11.15 (6.76) | 8.27 (6.44) | t = 5.33 | .000 |
| Use prescribed medication for sleep | 14 (4.5) | 9 (8.9) | 23 (5.6) | χ2 = 2.76 | .097 |
| Self-reported psychiatric disorder | 61 (19.7) | 22 (21.8) | 83 (20.2) | χ2 = 1.96 | .658 |
| Self-reported medical disorder | 217 (70.2) | 78 (77.2) | 295 (72.0) | χ2 = 1.85 | .174 |
| Mean yearly medical consultations (SD) | 3.74 (5.30) | 5.51 (9.83) | 4.17 (6.72) | t = 2.25 | .025 |
Data are n (%) unless otherwise indicated.
SD, standard deviation.