Table 2.

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.