Table 2.
Description of the groups based on the temporal pattern of sleep defined by the cluster analysis of the actigraphic variables (mean values±standard deviation) of time to sleep onset, sleep efficiency, sleep latency, and total sleep time (TST).
| Group 1 (morning type) | Group 2 (evening type) | Group 3 (undefined type) | P | |
| N(%) | 220 (61) | 116 (32) | 23 (7) | 0.001 |
| Age (years) | 44.4±14.4 | 40.3±13.5* | 43.6±17.2 | 0.04 |
| Gender (%) | ||||
| Male | 36.8 | 44 | 56.5 | 0.41 |
| Female | 63.2 | 56 | 43.5 | |
| BMI (kg/m2) | 26.7±5.7 | 26.5±5.2 | 27.8±7.1 | 0.58 |
| Occupation (%) | ||||
| Employed | 74.5 | 82 | 65.2 | 0.14 |
| Housewife | 8.2 | 4.3 | 8.7 | |
| Retired | 14.1 | 6.9 | 17.4 | |
| Unemployed | 3.2 | 2.6 | 8.7 | |
| Actigraphic variables | ||||
| Time of sleep onset (h:min) | 22:13‡ | 01:54 | Variable† | 0.001 |
| Sleep latency (min) | 11.9±9.4 | 11.1±9.9 | 25.2±20.1† | <0.001 |
| Sleep efficiency (%) | 81.0±6.4 | 81.5±6.5 | 72.3±5.5† | <0.001 |
| “24 h TST” (min) | 379.8±52.0‡ | 354.8±67.6 | 377.1±44.9 | 0.001 |
| “Main episode TST” (min) | 374.4±52.4‡ | 349.0±65.7 | 362.4±57.7 | 0.001 |
⁎
significant difference between the evening type group and the morning type and undefined type groups (ANOVA with Tukey post-hoc test).
†
significant difference between the undefined type group and the morning type and evening type groups (ANOVA with Tukey post-hoc test).
‡
significant difference between the morning type group and the evening type group (ANOVA with Tukey post-hoc test).