Table 1.

Characteristics of the study population

Control subjects (N = 47,591)Case subjects (N = 1,749)a
CharacteristicMeanSDMeanSD
Mean age at enrollment, SD55.19.056.78.8
n % n %
Race/ethnicity
 Non-Hispanic white40,46285.01,52787.3
 Non-Hispanic black4,3129.11136.5
 Hispanic1,5763.3533.0
 Other1,2312.6553.1
 Unknown60.000.0
Education
 Less than high school4941.0150.9
 Completed high school6,73514.223913.1
 Associate or technical degree16,18334.054130.9
 Bachelor's degree12,77326.848127.5
 Graduate degree11,39824.047227.0
 Unknown80.010.1
BMI
 <18.55601.2160.9
 18.5–24.917,89137.663636.4
 25.0–29.914,97531.556232.1
 30.0–39.911,81024.844425.4
 ≥40.02,3384.9915.2
 Unknown170.000.0
Smoking
 Never smoker25,48653.690551.7
 Former smoker18,04837.971240.6
 Current smoker3,9998.41317.5
 Unknown540.110.0
Physical activity (in Met-hours/week)
 1st Quintile9,44019.833619.2
 2nd Quintile9,44119.835820.5
 3rd Quintile9,43919.835920.5
 4th Quintile9,44019.835320.2
 5th Quintile9,44019.833018.9
 Unknown3910.8130.7
Hormone replacement therapy
 No, has never taken42,46589.21,50786.2
 Yes, is taking or took in the past4,92110.323513.4
 Unknown2050.470.4
  • aExcluding in situ breast cancer cases.