Circadian variations of hourly data of AAD onsets, fitted by Fourier model
| Group | N | Nocturnal trough | n | Morning peak | n | Afternoon peak | n | R squared | P value |
| Total | 1517 | 2:52 | 37.824±11.747 | 9:27 | 68.506±11.747 | 16:41 | 96.015±11.747 | 0.8151 | 0.0008 |
| Type A | 737 | 2:36 | 15.432±7.618 | 8:29 | 37.323±7.618 | 16:41 | 44.097±7.618 | 0.7203 | 0.0052 |
| Type B | 780 | 4:03 | 21.304±8.914 | 10:00 | 31.192±8.914 | 16:41 | 51.917±8.914 | 0.7204 | 0.0143 |
| Male | 1242 | 2:50 | 29.235±9.248 | 9:53 | 56.591±9.248 | 16:39 | 79.225±9.248 | 0.826 | 0.0004 |
| Female | 275 | 4:58 | 7.063±5.282 | 8:46 | 12.500±5.282 | 18:29 | 17.290±5.282 | 0.5518 | 0.1641 |
| Age <55 years | 875 | 4:07 | 23.327±10.628 | 8:54 | 40.316±10.628 | 16:51 | 52.087±10.628 | 0.5849 | 0.0803 |
| Age ≥55 years | 642 | 2:18 | 11.387±4.919 | 10:40 | 29.974±4.919 | 16:34 | 44.026±4.919 | 0.8766 | <0.0001 |
| Hypertensive | 929 | 3:02 | 23.861±9.927 | 7:00 | 36.635±9.927 | 16:50 | 61.886±9.927 | 0.7238 | 0.0088 |
| Normotensive | 577 | 1:57 | 13.552±4.843 | 9:32 | 34.235±4.843 | 16:14 | 33.659±4.843 | 0.8375 | 0.0002 |
Letter N indicates the number of cases in each group; letter n shows the number of cases fitted by Fourier model, presented by numbers±95% CIs; R square represents goodness of the model; and P, probability value resulting from the F statistic used to test hypothesis of straight-line model fitting.
AAD, acute aortic dissection.