Table 3. Association between sleep duration and incidence of stroke: crude incidence rate and adjusted hazard ratios.

Sex	Sleep duration (hours/day)	Number of cases (cases/total (%))		Crude incidence ratea	HR-age (95% CI)	HR-all (95% CI)
Men	–5.9	8/126	(2.4)	6.3	1.84 (0.86–3.94)	2.00 (0.93–4.31)
	6.0–6.9	17/478	(0.8)	3.4	1.24 (0.70–2.18)	1.13 (0.63–2.03)
	7.0–7.9	40/1258	(1.2)	3.0	1.00 (reference)	1.00 (reference)
	8.0–8.9	70/1653	(1.0)	3.9	1.11 (0.75–1.64)	1.03 (0.69–1.53)
	9.0–	72/898	(1.9)	7.9	1.60 (1.08–2.37)	1.39 (0.92–2.10)
Women	–5.9	6/256	(1.2)	2.2	1.06 (0.46–2.46)	0.97 (0.39–2.41)
	6.0–6.9	19/1118	(0.2)	1.6	0.75 (0.45–1.25)	0.68 (0.39–1.18)
	7.0–7.9	62/2548	(0.4)	2.2	1.00 (reference)	1.00 (reference)
	8.0–8.9	66/2213	(0.3)	2.7	0.89 (0.63–1.26)	0.86 (0.60–1.23)
	9.0–	51/819	(0.6)	5.9	1.39 (0.95–2.04)	1.29 (0.86–1.91)

HR-age: hazard ratios adjusted for age.

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

^aper 1000 person-years.