Table 1.

Study population characteristics

All study subjectsAll breast cancer cases
n (%)Person-years (%)n (%)
Age, y
    40-491,019,892 (31)2,113,932 (33)4,693 (25)
    50-591,072,392 (32)1,944,280 (31)5,648 (30)
    60-69683,529 (21)1,183,481 (19)4,575 (24)
    70-84555,931 (17)1,097,059 (17)4,203 (22)
Race
    White non-Hispanic2,386,452 (76)4,397,206 (76)14,148 (80)
    Hispanic white221,669 (7)420,360 (7)1,036 (6)
    African-American185,740 (6)399,959 (7)1,170 (7)
    Other325,792 (10)595,055 (10)1,401 (8)
    Missing212,091526,1721,364
Education
    ≤High school graduate/General Education Development883,554 (36)1,717,431 (37)5,339 (37)
    >High school1,596,254 (64)2,907,384 (63)9,170 (63)
    Missing851,9361,713,9374,610
Menopausal status
    Premenopausal716,485 (24)1,430,113 (25)2,990 (17)
    Perimenopausal55,084 (2)102,933 (2)212 (1)
    Postmenopausal2,265,421 (75)4,184,268 (73)14,660 (82)
    Missing294,754621,4381,257

NOTE: Multiple observations possible per woman in total but only one case observation per woman.