Table 1

Descriptive characteristics of cases and controls with available mammograms by ethnic group

VariableAll womenWhitesAfrican AmericansAsian Americans
CasesControlsPaCasesControlsPaCasesControlsPaCasesControlsPa
No. of subjects62244328022719914914367
Mean age, y49.349.50.7048.449.60.1049.349.90.5151.048.10.01
Mean BMI, kg/m225.025.90.00924.325.30.0227.527.90.5222.923.20.65
Mean age at menarche, y12.612.50.3212.512.30.1512.412.50.3413.012.90.56
First-degree breast cancer family history, %b15.19.50.00716.89.70.0214.18.70.1313.310.50.56
Parous, %b78.883.50.0573.978.90.2087.987.30.8575.591.00.008
Mean number of FFTPc2.02.20.051.72.00.062.52.50.731.92.30.10
Mean age at FFTPs, y24.623.70.0225.224.00.0221.721.10.3528.028.10.85
Menopause and HRT use, %b0.0050.010.260.03
 Premenopausal46.841.350.038.847.339.639.853.7
 Postmenopausal and
  never HRT use16.913.510.77.020.119.524.522.4
  current ERT use9.817.210.720.311.618.15.64.5
  current EPRT use11.714.916.521.68.55.47.013.4
  ex-ERT use6.96.33.94.87.010.712.61.5
  ex-EPRT use7.96.88.27.55.56.710.54.5
  • a P ascertained from t test, except where otherwise noted.

  • b P ascertained from Pearson χ2 test.

  • c FFTP, full-term pregnancy.