Table 1. Age and age-adjusted characteristics by age at menarche, reproductive duration,a oral contraceptive (OC) use, and parity in the Nurses' Health Study over the entire follow-up period.

	Age at menarche				Reproductive duration				OC use		Parity
	<12 years	12 years	13 years	>13 years	<36 years	36–38 years	39–40 years	41+ years	Never user	Ever user	Nulliparous	Parous
African–American (%)	1.3	1.2	1.1	1.3	1.0	1.0	1.0	0.9	1.3	1.2	1.6	1.2
Family history of glaucoma (%)	13.1	13.2	12.4	12.3	12.2	12.0	12.2	12.5	12.3	13.3	12.8	12.8
Hypertension (%)	39.2	35.8	33.7	31.9	37.5	37.6	38.6	41.2	33.3	37.0	34.7	35.1
Diabetes mellitus (%)	7.2	5.9	5.1	4.8	5.8	5.5	6.6	7.1	5.4	6.0	5.9	5.7
Current cigarette smoking (%)	15.5	14.9	15.1	16.1	19.2	15.4	12.9	9.0	15.9	14.7	17.2	15.2
Being in the top 25% of exercise (%)	24.5	24.0	24.7	25.6	25.4	25.7	26.6	26.2	24.0	25.5	25.9	24.6
Ever use of oral contraceptives (%)	50.3	50.1	50.7	49.0	42.7	42.9	42.8	43.8	0	100	36.8	50.9
Current use of postmenopausal hormones (%)	30.0	29.7	30.0	29.2	27.2	28.4	27.8	27.8	24.3	35.7	32.9	29.6
Being parous (%)	92.7	93.2	93.6	94.0	91.3	92.8	93.9	92.8	91.7	95.1	0	100
Mean alcohol intake (g/day)b	5.6	6.0	6.3	6.4	6.5	6.6	6.4	5.6	5.7	6.5	7.5	6.0
Mean caffeine intake (mg/day)b	324.4	322.6	321.0	319.5	331.9	318.0	308.8	292.5	329.9	314.9	318.3	322.1
Mean age at menarche (years)	10.7	12.0	13.0	14.6	13.2	12.7	12.2	11.5	12.5	12.5	12.4	12.5
Mean age at menopause (years)	55.6	56.6	56.8	56.6	45.7	49.7	51.6	52.9	56.1	56.9	53.7	56.6
Mean number of eye exams reported	5.9	5.9	5.9	5.6	5.9	6.0	6.1	6.2	5.3	6.3	5.6	5.9

^aDefined as the time interval from age at menarche to age at menopause among the subset of women with natural menopause.

^bCumulatively averaged intake.