Skip to main content

Table 8 Birth order distributions and odds ratios for breast cancer among white and African-American women by race

From: Birthweight, parental age, birth order and breast cancer risk in African-American and white women: a population-based case–control study

  Minimally adjusted ORa Fully adjusted ORb
  African-American White African-American White
  Case Control OR 95% CI Case Control OR 95% CI Case Control OR 95% CI Case Control OR 95% CI
Full CBCSc n = 331 n = 329    n = 523 n = 456    n = 331 n = 329    n = 523 n = 456   
   1st born (ref.) 106 103 Ref.   191 165 Ref.   106 103 Ref.   191 165 Ref.  
   2nd–4th born 142 151 0.8 0.6–1.2 264 226 1.0 0.7–1.3 142 151 0.8 0.6–1.2 264 226 1.0 0.7–1.3
   ≥5th born 83 75 1.0 0.7–1.5 68 65 1.0 0.7–1.5 83 75 1.0 0.7–1.5 68 65 1.0 0.7–1.5
   Mean ± SD 3.6 ± 2.7 3.3 ± 2.7    2.6 ± 1.9 2.6 ± 2.0           
   Median 2.0 3.3    2.0 2.0           
   Range 1–14 1–14    1–12 1–11           
Born ≥1948d,e n = 129 n = 134    n = 233 n = 181    n = 101 n = 109    n = 164 n = 115   
   1st born (ref.) 37 41 Ref.   80 67 Ref.   29 31 Ref.   55 45 Ref.  
   2nd–4th born 56 61 1.0 0.5–1.7 138 97 1.2 0.8–1.9 46 50 0.7 0.4–1.5 98 59 1.0 0.6–1.8
   ≥5th born 36 32 1.2 0.6–2.3 15 17 0.7 0.3–1.6 26 28 0.7 0.3–1.6 11 11 0.5 0.2–1.5
   Mean ± SD 3.6 ± 2.7) 3.3 ± 2.6)    2.3 ± 1.5) 2.3 ± 1.6)           
   Median 3.0 2.5    2.0 2.0           
   Range 1–14 1–14    1–10 1–11           
  1. 1Adjusted for age and sampling fractions. 2Adjusted for age, sampling fractions, and other covariates as specified. 3Additional covariates for fully adjusted OR: none. 4Additional covariates for fully adjusted OR: adult body mass index >25 kg/m2, household income ≥$30,000 and maternal age. 5Restricted to participants born on or after 1 January 1948. CBCS, Carolina Breast Cancer Study; CI, confidence interval; OR, odds ratio.
\