Table 3. Proportional hazard regression analysis of cardiovascular mortality in the study population with a basal selenium level of 65–85 μg/L (mean value) during an intervention time of four years.

Variable	Hazard ratio	95% CI	P-value
Male	1.04	0.50–2.20	0.91
Smoking	3.19	1.24–8.21	0.02
IHD	2.05	0.96–4.41	0.06
EF<40%	2.84	1.17–6.89	0.02
Active treatment	0.38	0.15–0.92	0.03

Notes: CI: Confidence interval; COPD; EF: Ejection fraction. EF as obtained by echocardiography; IHD: Ischemic heart disease.