Table 1

Baseline characteristics of studied women from the WHI OS study

Infertility, n (%) (N=88 732)Age at menopause, n (%) (N=79 690)
YesNop Value<50≥50p Value
N (%)13 621 (15.4)75 111 (84.6)35 834 (45.0)43 856 (55.0)
Age (years)
 <604433 (32.5)23 951 (31.9)<0.00113 112 (36.6)12 550 (28.6)<0.001
 60 to <705793 (42.5)33 216 (44.2)14 468 (40.4)20 516 (46.8)
 ≥703395 (24.9)17 944 (23.9)8254 (23.0)10 790 (24.6)
BMI at age 18 (kg/m²)
 <206486 (48.5)32 493 (44.3)<0.00116 252 (46.4)18 965 (44.2)<0.001
 20 to <266418 (48.0)37 870 (51.7)17 392 (49.6)22 357 (52.1)
 26 to <30333 (2.5)2006 (2.7)946 (2.7)1104 (2.6)
 ≥30137 (1.0)941 (1.3)458 (1.3)462 (1.1)
Ethnicity
 Caucasian (non-Hispanic)11 681 (86.0)62 555 (83.5)<0.00129 618 (82.9)37 670 (86.1)<0.001
 African-American861 (6.3)6232 (8.3)3180 (8.9)2754 (6.3)
 Hispanic388 (2.9)2898 (3.9)1452 (4.1)1348 (3.1)
 Other648 (4.8)3229 (4.3)1489 (4.2)1964 (4.5)
Education
 <HS526 (3.9)3921 (5.3)<0.0011975 (5.6)1738 (4.0)<0.001
 HS graduate/some college7134 (52.8)39 354 (52.8)19 749 (55.6)21 513 (49.4)
 College degree or more5843 (43.3)31 259 (41.9)13 819 (38.9)20 281 (46.6)
Alcohol use*
 Never1448 (10.7)8943 (11.9)<0.0014257 (11.9)4794 (11.0)<0.001
 Ever12 128 (89.3)65 905 (88.1)31 420 (88.1)38 876 (89.0)
Alcohol use
 Non-drinker1386 (10.2)8456 (11.3)<0.0014041 (11.3)4540 (10.4)<0.001
 Ex-drinker2445 (18.0)14 156 (19.0)7132 (20.0)7311 (16.8)
 <1 drink/month1588 (11.7)8650 (11.6)4101 (11.5)5040 (11.6)
 <1 drink/week2819 (20.8)14 884 (19.9)7158 (20.1)8804 (20.2)
 1 to <7 drinks/week3443 (25.4)19 287 (25.8)8804 (24.7)12 004 (27.5)
 7 or more drinks/week1881 (13.9)9256 (12.4)4396 (12.3)5895 (13.5)
Age at menarche
 Mean (SD)12.6 (1.5)12.6 (1.5)<0.00112.6 (1.5)12.6 (1.5)<0.001
OC use ever
 No8201 (60.2)44 604 (59.4)0.07220 789 (58.0)26 298 (60.0)<0.001
 Yes5420 (39.8)30 506 (40.6)15 044 (42.0)17 558 (40.0)
Insecticide exposure ever
 No4610 (36.1)27 966 (39.9)<0.00112 710 (38.1)16 346 (39.6)<0.001
 Yes8157 (63.9)42 146 (60.1)20 616 (61.9)24 907 (60.4)
Very hard exercise 3 times/week at age 18
 No7134 (54.3)39 844 (55.1)0.08518 703 (54.3)23 830 (56.3)<0.001
 Yes6000 (45.7)32 429 (44.9)15 759 (45.7)18 477 (43.7)
Smoking status
 Never-smoker6615 (49.2)37 945 (51.1)<0.00117 157 (48.5)22 648 (52.3)<0.001
 Past smoker5951 (44.3)31 641 (42.6)15 461 (43.7)18 556 (42.8)
 Current smoker879 (6.5)4637 (6.2)2764 (7.8)2113 (4.9)
SHS in never-smoker†
 None573 (8.7)3577 (9.4)<0.0011499 (8.7)2211 (9.8)<0.001
 Childhood only357 (5.4)2240 (5.9)1029 (6.0)1317 (5.8)
 Adult home only398 (6.0)2439 (6.4)1043 (6.1)1464 (6.5)
 Adult work only798 (12.1)4806 (12.7)2079 (12.1)2960 (13.1)
 Childhood + adult home660 (10.0)4120 (10.9)1837 (10.7)2449 (10.8)
 Childhood + adult work713 (10.8)3914 (10.3)1838 (10.7)2300 (10.2)
 Adult home + work895 (13.5)5124 (13.5)2364 (13.8)3032 (13.4)
 Childhood + adult home + work2221 (33.6)11 725 (30.9)5468 (31.9)6915 (30.5)
SHS exposure quantified†
 None573 (8.7)3577 (9.5)0.0141499 (8.8)2211 (9.8)<0.001
 No childhood + any adult2074 (31.6)12 271 (32.6)5440 (32.0)7406 (32.9)
 Childhood <10 years + any adult583 (8.9)3429 (9.1)1567 (9.2)2022 (9.0)
 Childhood ≥10 years + adult home
<20 years + adult work <10 years
1592 (24.2)8695 (23.1)4012 (23.6)5290 (23.5)
 Childhood ≥10 years + adult home
<20 years + adult work ≥10 years
687 (10.5)3727 (9.9)1741 (10.2)2159 (9.6)
 Childhood ≥10 years + adult home
≥20 years + adult work <10 years
515 (7.8)3106 (8.3)1419 (8.3)1799 (8.0)
 Childhood ≥10 years + adult home
≥20 years + adult work ≥10 years
544 (8.3)2833 (7.5)1337 (7.9)1600 (7.1)
Age started smoking (years)
 Never-smoker, SHS none573 (4.2)3577 (4.8)<0.0011499 (4.2)2211 (5.1)<0.001
 Never-smoker, SHS6042 (44.8)34 368 (46.1)15 658 (44.1)20 437 (47.0)
 <15452 (3.3)2376 (3.2)1304 (3.7)1217 (2.8)
 15–193437 (25.5)18 183 (24.4)9189 (25.9)10 402 (23.9)
 20–242235 (16.6)11 336 (15.2)5590 (15.7)6678 (15.4)
 25–29451 (3.3)2492 (3.3)1229 (3.5)1367 (3.1)
 ≥30306 (2.3)2147 (2.9)1030 (2.9)1134 (2.6)
Average cigarette/day
 Never-smoker, SHS none573 (4.3)3577 (4.9)<0.0011499 (4.3)2211 (5.2)<0.001
 Never-smoker, SHS6042 (45.7)34 368 (47.1)15 658 (45.0)20 437 (48.0)
 <51445 (10.9)8311 (11.4)3825 (11.0)4939 (11.6)
 5–142079 (15.7)11 150 (15.3)5454 (15.7)6451 (15.1)
 15–241876 (14.2)9490 (13.0)4987 (14.3)5309 (12.5)
 ≥251197 (9.1)6095 (8.4)3361 (9.7)3237 (7.6)
  • Categories for some variables do not add up to the total n because of missing value.

  • *Twelve drinks ever in lifetime.

  • †In never-smokers.

  • BMI, body mass index; HS, high school; OC, oral contraceptive; OS, Observational Study; SHS, secondhand smoke; WHI, Women's Health Initiative.