Table 4.

Characteristics of women who had never smoked or were former smokers, according to age when they quit smoking

		Age at quitting (years)
	Never smoked	<35	35-54	≥55	Unknown
No of participants	326 826	47 067	59 804	16 815	1753
White (%)	92.7	95.4	94.8	95.6	88.7
Educated to ≤high school (%)	46.1	28.3	35.5	45.2	43.5
Married (%)	75.9	85.8	79.8	60.5	69.9
Most recent/current job—blue collar (%)	9.4	6.8	7.0	8.0	10.2
Vitamin use:
A (%)	9.0	10.8	10.5	8.4	10.9
E (%)	19.4	22.0	23.8	20.6	20.8
C (%)	26.3	31.2	31.4	27.4	28.3
Mean servings of vegetables and citrus fruit a week	28.9	29.9	30.6	30.2	29.4
Occupational exposure to asbestos (%)	1.8	0.9	1.3	2.1	2.4
Cigarettes smoked a day (%):
1-9		38.5	23.9	18.6	35.5
10-19		22.0	22.6	21.3	11.4
20		18.8	25.2	27.5	10.5
21-39		5.0	9.3	9.0	2.1
40		3.8	7.2	8.1	1.9
≥41		1.5	3.4	3.2	1.9
Mean		13.1	17.8	19.0	11.7
Age (years) when started smoking (%):
<16		10.1	9.4	7.6	5.0
16-17		22.3	19.5	16.1	9.9
18-20		46.5	37.2	28.3	20.5
≥21		20.1	32.5	44.5	22.0
Mean		18.7	20.6	23.2	22.1