Table 4.

Mortality from Phase 3 Onwards by Change in the Number of Hours Sleep Between Phase 1 and Phase 3

Cause of death	Change in hours of sleep between Phase 1 and Phase 3
	Increase from 5 or 6 hoursa	Reference group (No change in hours)	Decrease from 6, 7, or 8 hoursb	Increase from 7 or 8 hoursc
All-causes
Number of deaths	55		57	58
Hazard ratio (95% CI) - Age adjusted	0.88 (0.60–1.28)	1.0	1.72 (1.25–2.38)	1.84 (1.31–2.58)
Hazard ratio (95% CI) - Fully adjusted #	0.92 (0.63–1.35)	1.0	1.62 (1.17–2.25)	1.75 (1.24–2.47)
CVD
Number of deaths	16		24	12
Hazard ratio (95% CI) - Age adjusted	0.74 (0.37–1.46)	1.0	2.39 (1.41–4.05)	1.29 (0.64–2.59)
Hazard ratio (95% CI) - Fully adjusted #	0.85 (0.42–1.70)	1.0	2.04 (1.20–3.49)	1.22 (0.60–2.48)
Non-CVD
Number of deaths	38		33	45
Hazard ratio (95% CI) - Age adjusted	0.97 (0.61–1.54)	1.0	1.48 (0.98–2.23)	2.09 (1.40–3.12)
Hazard ratio (95% CI) - Fully adjusted #	0.98 (0.62–1.57)	1.0	1.44 (0.95–2.18)	2.06 (1.38–3.08)

^#Fully adjusted hazard ratios are adjusted for the following Phase 3 measures:- age, sex, marital status, employment grade, smoking status, physical activity, alcohol consumption, self-rated health, body mass index, systolic blood pressure, cholesterol, physical illness, modified GHQ score, prevalent CHD

^a5 or 6 hours sleep at Phase 1 and >5 or 6 hours respectively at Phase 3, reference is either 5 or 6 hours at both phases (44 deaths)

^b6, 7, or 8 hours sleep at Phase 1 and <6, 7, or 8 hours respectively at Phase 3, reference is 6, 7, or 8 hours at both phases (111 deaths)

^c7 or 8 hours sleep at Phase 1 and >7 or 8 hours, respectively, at Phase 3; reference is either 7 or 8 hours at both phases (76 deaths)