Table 2 Sleep habits on school days and free days in university students in Japan
Japanese | High CCT (n = 275) | Low CCT (n = 172) | P value |
|---|---|---|---|
Sleep habits (school days) | |||
  Bedtime | 01:13 (0:58) | 01:00 (1:04) | 0.029 * |
 Sleep latency (min) | 15.5 (11.8) | 15.1 (10.7) | 0.668 |
 Sleep onset time | 01:29 (1:00) | 01:15 (1:05) | 0.026 * |
 Wake time | 08:02 (1:13) | 07:59 (1:10) | 0.476 |
 Midpoint of sleep | 04:45 (0:57) | 4:37 (0:59) | 0.100 |
 Sleep period time (h) | 6.55 (1.14) | 6.74 (1.11) | 0.186 |
Sleep habits (free days) | |||
  Bedtime | 01:45 (1:13) | 01:25 (1:11) | 0.003 ** |
 Sleep latency (min) | 16.1 (13.3) | 16.1 (12.6) | 0.949 |
 Sleep onset time | 02:02 (1:16) | 01:41 (1:11) | 0.003 ** |
 Wake time | 09:41 (1:27) | 09:26 (1:20) | 0.052 |
 Midpoint of sleep | 05:51 (1:11) | 05:33 (1:08) | 0.006 ** |
 Sleep period time (h) | 7.65 (1.33) | 7.74 (1.12) | 0.495 |
Social jet lag (h) | 1.09 (0.84) | 0.94 (0.78) | 0.051 |