Table 4. Difference in cardiovascular mortality within 5, 10 and 12 years after intervention of selenium and coenzyme Q10 combined or placebo for four years.

Follow-up time	Mortality in active treatment group (%)	Mortality in placebo group (%)	χ2-value	P-value
5 years	5.9	12.6	5.97	0.015
10 years	20.8	38.7	17.01	<0.0001
12 years	28.1	45.0	13.78	0.0002