Table 3.

Association between exposure to overtime work at baseline and incident coronary heart disease, as indicated by coronary death or incident non-fatal myocardial infarction: the Whitehall II study

Exposure: overtime work/day	Fatal CHD or non-fatal myocardial infarction
	No. of events	No. of Participants	Person-years	Rate/1000 person-years	Model A, HR (95% CI)a	P-value	Model B, HR (95% CI)b	P-value	Model C, HR (95% CI)c	P-value	Model D, HR (95% CI)d	P-value	Model E, HR (95% CI)e	P-value
All	159	6014	68893.0	2.31
No overtime	81	3256	37015.1	2.19	1.00	Ref.	1.00	Ref.	1.00	Ref.	1.00	Ref.	1.00	Ref.
1 h	27	1247	14456.5	1.87	0.95 (0.61–1.49)	0.84	1.01 (0.65–1.58)	0.97	0.99 (0.63–1.55)	0.96	0.96 (0.61–1.52)	0.87	0.93 (0.59–1.47)	0.75
2 h	27	894	10310.7	2.62	1.46 (0.93–2.30)	0.10	1.51 (0.96–2.38)	0.07	1.39 (0.88–2.18)	0.16	1.34 (0.84–2.13)	0.22	1.26 (0.79–2.02)	0.33
3–4 h	24	617	7110.7	3.38	1.90 (1.17–3.06)	0.009	1.98 (1.22–3.20)	0.005	1.79 (1.11–2.90)	0.018	1.76 (1.07–2.88)	0.026	1.67 (1.02–2.76)	0.043

^aModel A: adjusted for age, sex, marital status, and occupational grade. Likelihood ratio (df = 11) for the overall model 75.1, P < 0.0001.

^bModel B: as Model A and additionally adjusted for diabetes, systolic and diastolic blood pressure, LDL and HDL cholesterol, and triglycerides. Likelihood ratio (df = 19) for the overall model 169.1, P < 0.0001.

^cModel C: as Model B and additionally adjusted for smoking, alcohol use, fruit and vegetable consumption, exercise level, body mass index, and sleeping hours. Likelihood ratio (df = 28) for the overall model 201.9, P < 0.0001.

^dModel D: as Model C and additionally adjusted for sickness absence, psychological distress, job demands, and decision latitude at work. Likelihood ratio (df = 35) for the overall model 208.1, P < 0.0001.

^eModel E: as Model D and additionally adjusted for type A behaviour pattern. Likelihood ratio (df = 37) for the overall model 210.8, P < 0.0001.