Skip to main content

Advertisement

Table 3 Characteristics of the study cohort: Reproductive factors

From: Predictors of competing mortality to invasive breast cancer incidence in the Canadian National Breast Screening study

Variable n = 89434(%)
Age at menarche  
 9-10 2675 (2.99)
 11-13 59433 (66.46)
 14-16 26231 (29.33)
 17-18 1095 (1.22)
Still have periods  
 Yes 39281 (43.92)
 No 50153 (56.08)
Menstrual status  
 Pre-menopause 49201 (55.01)
 Post-menopause 40233 (44.99)
Menstruation length (years) (mean±SD) 32.10(±5.85)
Number of live births  
 Nulliparous 13173 (14.73)
 1-2 32781 (36.65)
 3-4 33952 (37.96)
 > = 5 9528 (10.66)
Regular periods  
 Yes 70635 (78.98)
 No 18799 (21.02)
Had a hysterectomy  
 Yes 27584 (30.84)
 No 27584 (69.16)
Had a bi-lateral oophorectomy  
 Yes 9567 (10.70)
 No 79867 (89.30)
Ever pregnant  
 Yes 78870 (88.19)
 No 10564 (11.81)
Number of pregnancies  
 0 13173 (14.73)
 1-2 23050 (25.77)
 3-4 34721 (38.82)
 5-10 17966 (20.09)
 11-17 524 (0.59)
Pregnancies lasted < 4 months  
 0 60228 (67.35)
 1-2 25563 (28.58)
 3-4 2998 (3.35)
 5-10 645 (0.72)
Age at first child birth  
 N/A 13173 (14.73)
 14-19 8345 (9.33)
 20-25 42234 (47.22)
 26-30 18756 (20.97)
 31-34 4683 (5.24)
 35-39 2011 (2.25)
 40-49 232 (0.26)