Table 2. Association between sleep duration and all-cause mortality: crude mortality rate and adjusted hazard ratios.

Sex	Sleep duration (hours/day)			Crude mortality rate (per 1000 person-years)	HR-age (95% confidence interval)	HR-all (95% confidence interval)
Males		-	5.9	15.6	2.3 (1.3-3.9)	2.4 (1.3-4.2)
	6.0	-	6.9	6.0	1.1 (0.7-1.8)	1.1 (0.7-1.8)
	7.0	-	7.9	5.9	1.0 (reference)	1.0 (reference)
	8.0	-	8.9	6.8	1.0 (0.7-1.3)	0.9 (0.6-1.2)
	9.0	-		12.7	1.3 (0.9-1.8)	1.1 (0.8-1.6)
Females		-	5.9	1.9	0.8 (0.3-2.2)	0.7 (0.2-2.3)
	6.0	-	6.9	3.1	1.3 (0.8-2.0)	1.3 (0.8-2.1)
	7.0	-	7.9	2.6	1.0 (reference)	1.0 (reference)
	8.0	-	8.9	3.7	1.0 (0.7-1.5)	1.1 (0.8-1.6)
	9.0	-		7.9	1.5 (1.0-2.3)	1.5 (1.0-2.4)

HR-age : hazard ratios adjusted for age.

HR-all : hazard ratios adjusted for age, systolic blood pressure, total cholesterol, body mass index, smoking habits, alcohol drinking habits, education, and marital status.