Baseline characteristics of the study population stratified by insomnia symptoms
| Insomnia symptoms* | ||
| No | Yes | |
| Participants, no. | 11 775 | 2397 |
| Age, mean±SD, years | 43.5±12.0 | 47.0±11.8 |
| Body mass index, mean±SD, kg/m2 | 25.7±4.1 | 26.0±4.4 |
| Obese, % (no.) | 13.8 (1621) | 16.0 (383) |
| Leisure time physical activity, % (no.) | ||
| Low† | 15.5 (1820) | 20.4 (490) |
| Moderate‡ | 35.5 (4185) | 38.3 (917) |
| High§ | 49.0 (5770) | 41.3 (990) |
| Education≥13 years, % (no.) | 26.0 (3059) | 23.3 (559) |
| Unknown | 1.0 (120) | 1.5 (35) |
| Depression and/or anxiety (HADS score ≥8), % (no.) | 11.8 (1385) | 34.1 (817) |
| Unknown | 10.7 (1265) | 15.0 (359) |
| Current smoker, % (no.) | 15.7 (1852) | 18.7 (447) |
| Unknown | 20.4 (2407) | 23.1 (554) |
*Participants were classified with insomnia symptoms if they answered ‘Often/always’ on at least one of the questions about ‘Problems falling asleep’ and ‘Waking up too early’ or ‘Yes’ on the question about ‘Impaired work ability due to sleep problems’.
†Defined as <1-hour light activity per week.
‡Defined as ≥1-hour light and no hard activity.
§Defined as any hard activity.
HADS, Hospital Anxiety and Depression Scale.