Table 1.
Baseline characteristics by recreational physical activity in the Prospective Family Study Cohort (N=15,550)
| Quintiles of Age-Adjusted Baseline Recreational Physical Activity | |||||
|---|---|---|---|---|---|
| Baseline characteristic | Q1 | Q2 | Q3 | Q4 | Q5 |
| Age, years, mean (sd) | 47.8 (15.3) | 42.9 (14.3) | 43.8 (14.2) | 45.7 (14.7) | 51.1 (14.7) |
| Premenopausal, n (%) | 1,704 (54.7) | 2,084 (67.1) | 2,099 (67.4) | 1,829 (58.9) | 1,458 (47.0) |
| Race and ethnicity, n (%) | |||||
| non-Hispanic white | 2,350 (75.4) | 2,451 (78.9) | 2,506 (80.5) | 2,426 (78.1) | 2,418 (77.9) |
| other | 745 (23.9) | 626 (20.2) | 582 (18.7) | 652 (21.0) | 662 (21.3) |
| missing | 23 (0.7) | 30 (1.0) | 27 (0.9) | 29 (0.9) | 23 (0.7) |
| Education, n (%) | |||||
| high school/GED or less | 1,392 (44.6) | 904 (29.1) | 865 (27.8) | 847 (27.3) | 968 (31.2) |
| College or more | 1,708 (54.8) | 2,193 (70.6) | 2,245 (72.1) | 2,246 (72.3) | 2,123 (68.4) |
| Missing | 18 (0.6) | 10 (0.3) | 5 (0.2) | 14 (0.5) | 12 (0.4) |
| Parity/breastfeeding, n (%) | |||||
| nulliparous | 568 (18.2) | 850 (27.4) | 877 (28.2) | 854 (27.5) | 685 (22.1) |
| parous 1–2/No BF | 454 (14.6) | 383 (12.3) | 338 (10.9) | 367 (11.8) | 359 (11.6) |
| parous 1–2/BF | 813 (26.1) | 853 (27.5) | 878 (28.2) | 861 (27.7) | 836 (26.9) |
| parous 3+/No BF | 330 (10.6) | 219 (7.1) | 188 (6.0) | 213 (6.9) | 288 (9.3) |
| parous 3+/BF | 953 (30.6) | 802 (25.8) | 834 (26.8) | 812 (26.1) | 935 (30.1) |
| Cigarette use, n (%) | |||||
| never | 1,694 (54.3) | 1,830 (58.9) | 1,856 (59.6) | 1,820 (58.6) | 1,802 (58.1) |
| former | 790 (25.3) | 750 (24.1) | 816 (26.2) | 874 (28.1) | 950 (30.6) |
| current | 606 (19.4) | 495 (15.9) | 403 (12.9) | 384 (12.4) | 324 (10.4) |
| missing | 28 (0.9) | 32 (1.0) | 40 (1.3) | 29 (0.9) | 27 (0.9) |
| Alcohol use, n (%) | |||||
| never | 1,760 (56.5) | 1,625 (52.3) | 1,462 (46.9) | 1,510 (48.6) | 1,461 (47.1) |
| former | 525 (16.8) | 477 (15.4) | 490 (15.7) | 450 (14.5) | 409 (13.2) |
| current | 818 (26.2) | 974 (31.4) | 1,130 (36.3) | 1,116 (35.9) | 1,208 (38.9) |
| missing | 15 (0.5) | 31 (1.0) | 33 (1.1) | 31 (1.0) | 25 (0.8) |
| Menopausal hormone therapy, n (%) | |||||
| never | 2,325 (74.6) | 2,482 (79.9) | 2,473 (79.4) | 2,321 (74.7) | 2,128 (68.6) |
| former | 389 (12.5) | 280 (9.0) | 314 (10.1) | 381 (12.3) | 458 (14.8) |
| current | 366 (11.7) | 316 (10.2) | 289 (9.3) | 370 (11.9) | 487 (15.7) |
| missing | 38 (1.2) | 29 (0.9) | 39 (1.3) | 35 (1.1) | 30 (1.0) |
| Hormonal birth control, n (%) | |||||
| never | 777 (24.9) | 705 (22.7) | 611 (19.6) | 660 (21.2) | 846 (27.3) |
| former | 1,955 (62.7) | 1,878 (60.4) | 1,963 (63.0) | 1,980 (63.7) | 1,939 (62.5) |
| current | 357 (11.5) | 509 (16.4) | 519 (16.7) | 453 (14.6) | 302 (9.7) |
| missing | 29 (0.9) | 15 (0.5) | 22 (0.7) | 14 (0.5) | 16 (0.5) |
| Body mass index, n (%) | |||||
| <25 kg/m2 | 1,342 (43.0) | 1,577 (50.8) | 1,675 (53.8) | 1,722 (55.4) | 1,796 (57.9) |
| 25–<30 kg/m2 | 832 (26.7) | 799 (25.7) | 807 (25.9) | 826 (26.6) | 863 (27.8) |
| ≥30 kg/m2 | 858 (27.5) | 653 (21.0) | 586 (18.8) | 514 (16.5) | 393 (12.7) |
| missing | 86 (2.8) | 78 (2.5) | 47 (1.5) | 45 (1.5) | 51 (1.64) |
| Lifetime familial BC risk, mean (sd) | 23.8 (16.9) | 24.6 (17.6) | 24.1 (16.7) | 24.4 (17.0) | 23.6 (16.1) |
| Adolescent RPA, n (%) | |||||
| none | 528 (16.9) | 97 (3.1) | 117 (3.8) | 111 (3.6) | 88 (2.8) |
| any | 2,449 (78.5) | 2,828 (91.0) | 2,820 (90.5) | 2,839 (91.4) | 2,742 (88.4) |
| missing | 141 (4.5) | 182 (5.9) | 178 (5.7) | 157 (5.1) | 273 (8.08) |
Notes: BC=breast cancer, sd=standard deviation; GED=general education degree; BF=breast feeding; BOADICEA=Breast Ovarian Analysis of Disease Incidence and Carrier Estimation Algorithm; RPA=recreational physical activity. Refer to eTable 1 in the supplemental materials for the minimum number of metabolic equivalents (METs) required to be classified as active for a given age at baseline.