Table 2.

Univariate Cox regression on disease-free interval for alignment of bedtime among 85 subjects with metastatic breast cancer.

	B	SE	χ2f	df	p	Hazard Ratio	95% Confidence Interval
Age at initial diagnosisa	0.040	0.016	5.762	1	0.016	1.040	1.008–1.074
Stage at initial diagnosis (reference: III)			1.514	3	0.679
0	−0.413	0.522	0.665	1	0.415	0.661	0.238–1.841
I	−0.376	0.322	1.305	1	0.253	0.687	0.365–1.291
II	−0.354	0.313	1.212	1	0.271	0.702	0.380–1.298
Estrogen receptor, negative	0.854	0.294	7.119	1	0.008	2.349	1.319–4.183
Progesterone receptor, negativec	0.380	0.250	2.185	1	0.139	1.462	0.896–2.388
HER2, negatived	0.105	0.277	0.145	1	0.704	1.110	0.644–1.912
Surgery before metastasis	−0.569	0.466	1.273	1	0.259	0.566	0.227–1.412
Chemotherapy before metastasis	0.072	0.227	0.103	1	0.749	1.075	0.689–1.677
Radiation therapy before metastasis	−0.039	0.222	0.032	1	0.859	0.961	0.623–1.485
Hormonal therapy before metastasis	−0.049	0.221	0.049	1	0.824	0.952	0.618–1.467
Natural-killer cell count,b lowere	0.0517	0.244	4.467	1	0.035	1.676	1.039–2.704
Chronotype score (reference: neither type)			3.281	2	0.194
Morning type	−0.267	0.230	1.338	1	0.247	0.766	0.488–1.201
Evening type	0.510	0.449	1.150	1	0.284	1.665	0.691–4.012
Misalignment of bedtime (“Going to bed earlier or later than preferred bedtime’)	1.045	0.325	8.611	1	0.003	2.844	1.504–5.378

^aContinuous variables

^bNatural-killer cell count was classified into higher and lower one by median value of 116.97/mm³ (n = 72)

^cn=81;

^dn=75;

^en=72.

^fLikelihood ratio test was performed