Light smoking at base-line predicts a higher mortality risk to women than to men; evidence from a cohort with long follow-up

Table 2 Hazard ratios (HR) for all-cause mortality to 31 ^st December 2007 from the regression models

			Weibull model^*				Cox model		Proportional hazards assumption
	HR		95% CI	P	HR		95% CI	P	ρ	P
Never smoked	1.00				1.00
Light smoker	1.21	1.00	1.46	.051	1.21	1.00	1.46	.055	-0.012	.60
Medium smoker	1.68	1.38	2.05	<.001	1.64	1.34	2.00	<.001	0.000	.99
Heavy smoker	2.01	1.51	2.68	<.001	1.99	1.49	2.65	<.001	-0.042	.06
Former smoker	0.89	0.66	1.21	.465	0.89	0.66	1.22	.475	-0.012	.60
Male	1.00				1.00
Female	1.10	0.92	1.32	.304	1.07	0.89	1.29	.471	-0.020	.36
Light smoker RRR	1.35	1.07	1.70	.012	1.35	1.07	1.70	.012	-0.008	.71
Medium smoker RRR	1.13	0.87	1.46	.361	1.15	0.89	1.49	.290	-0.029	.19
Heavy smoker RRR	0.98	0.61	1.58	.942	1.00	0.63	1.61	.990	-0.021	.35
Former smoker RRR	1.11	0.68	1.80	.681	1.10	0.68	1.78	.705	-0.026	25
Byssinosis absent	1.00				1.00
Byssinosis present	1.04	0.93	1.16	.484	1.04	0.93	1.15	.535	-0.010	.67
Cough and phlegm absent	1.00				1.00
Cough and phlegm present	1.07	0.97	1.18	.158	1.07	0.97	1.18	.155	0.031	.17
One decade in the cotton industry	0.91	0.88	0.94	<.001	0.91	0.88	0.95	<.001	0.047	.04
FEV₁: 10% decrease below normal	1.07	1.04	1.10	<.001	1.07	1.04	1.10	<.001	0.014	.54
FEV₁ to FVC ratio: decrease of 10%	1.01	0.95	1.07	.763	1.01	0.96	1.07	.726	0.001	.97

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