Table 1.

Distribution of participants by age and sex in the source population, the initial random sample and the CoLaus Study participants.

	Source population (n = 56,694)	Random sample (n = 19,830)	CoLaus Study (n = 6,188)
Women (%)	30,141 (53.4)	10,601 (53.5)	3,251 (52.5)
P value		0.79	0.08
Age (years)	52.0 ± 11.6	50.8 ± 11.5	51.1 ± 10.9
P value		<0.001	<0.001
Age group
35–44	18.877 (33.4)	7,265 (36.6)	2,051 (33.1)
45–54	14,614 (25.9)	5,202 (26.2)	1,682 (27.2)
55–64	12.484 (22.1)	4,417 (22.3)	1,657 (26.8)
65–75	10,524 (18.6)	2,946 (14.9)	798 (12.9)
P value		<0.001	<0.001

Results are expressed as number of subjects and (percentage) or as mean ± SD. Statistical analysis by Student's t-test or chi-square test compared to the source population