Table 3.

Effects of sleep duration on incidence of cancer grouped by age

Characteristic	Age<=60					Age>60
	N	Event N	HR1	95% CI1	p-value	N	Event N	HR1	95% CI1	p-value	p for interaction
Overall cancer
Nocturnal sleep duration (hours)	6,675	180				3,321	145
6-9	3,352	81	—	—		1,409	60	—	—
<6	3,054	87	1.14	0.84, 1.55	0.389	1,773	81	1.10	0.78, 1.54	0.588	0.608
>9	269	12	1.81	0.98, 3.32	0.056	139	4	0.71	0.26, 1.98	0.517	0.235
Day time sleep duration(minutes)	6,675	180				3,321	145
≤30	4,339	113	—	—		2,085	83	—	—
>30	2,336	67	1.10	0.81, 1.49	0.545	1,236	62	1.17	0.84, 1.64	0.348	0.515
Total sleep duration(hours)	6,675	180				3,321	145
6-9	3,800	87	—	—		1,620	66	—	—
<6	2,223	72	1.35	1.00, 1.85	0.049	1,334	59	1.15	0.80, 1.64	0.454	0.414
>9	652	21	1.42	0.88, 2.28	0.153	367	20	1.42	0.86, 2.35	0.174	0.989
Digestive&Respiratory_System
Nocturnal sleep duration (hours)	6,675	92				3,321	92
6-9	3,352	38	—	—		1,409	41	—	—
<6	3,054	48	1.28	0.83, 1.96	0.259	1,773	49	1.10	0.78, 1.54	0.588	0.169
>9	269	6	1.91	0.81, 4.53	0.142	139	2	0.71	0.26, 1.98	0.517	0.359
Day time sleep duration(minutes)	6,675	92				3,321	92
≤30	4,339	59	—	—		2,085	51	—	—
>30	2,336	33	0.98	0.64, 1.51	0.935	1,236	41	1.17	0.84, 1.64	0.348	0.390
Total sleep duration(hours)	6,675	92				3,321	92
6-9	3,800	39	—	—		1,620	43	—	—
<6	2,223	42	1.83	1.18, 2.83	0.007	1,334	37	1.15	0.80, 1.64	0.454	0.062
>9	652	11	1.58	0.81, 3.08	0.182	367	12	1.42	0.86, 2.35	0.174	0.517
Other System
Nocturnal sleep duration (hours)	6,675	85				3,321	55
6-9	3,352	43	—	—		1,409	21	—	—
<6	3,054	36	0.93	0.60, 1.46	0.761	1,773	32	0.97	0.64, 1.48	0.894	0.567
>9	269	6	1.61	0.68, 3.79	0.280	139	2	0.49	0.12, 2.05	0.330	0.400
Day time sleep duration(minutes)	6,675	85				3,321	55
≤30	4,339	51	—	—		2,085	34	—	—
>30	2,336	34	1.26	0.81, 1.95	0.309	1,236	21	1.20	0.79, 1.83	0.392	0.775
Total sleep duration(hours)	6,675	85				3,321	55
6-9	3,800	49	—	—		1,620	24	—	—
<6	2,223	26	0.83	0.51, 1.34	0.440	1,334	23	1.10	0.71, 1.72	0.670	0.378
>9	652	10	1.19	0.60, 2.35	0.618	367	8	1.22	0.64, 2.33	0.541	0.729