Table 2. Baseline Characteristics by Initial Fracture Locationa for 66 874 Participants.
| Characteristic | No. (%) | P value | ||||
|---|---|---|---|---|---|---|
| No fracture (n = 59 732) | Traumatic (n = 1624) | Nontraumatic (n = 3891) | Unknown trauma (n = 1627) | Fracture vs no fracture | Traumatic vs nontraumatic vs unknown trauma | |
| Age at enrollment, mean (SD), y | 63.1 (7.0) | 64.0 (7.0) | 65.6 (7.2) | 65.8 (7.2) | ||
| <55 | 7139 (12.0) | 147 (9.1) | 311 (8.0) | 116 (7.1) | <.001 | <.001 |
| 55 to <60 | 12 594 (21.1) | 327 (20.1) | 552 (14.2) | 222 (13.6) | ||
| 60 to <65 | 14 942 (25.0) | 384 (23.6) | 768 (19.7) | 346 (21.3) | ||
| 65 to <69 | 13 095 (21.9) | 377 (23.2) | 993 (25.5) | 411 (25.3) | ||
| 70 to <75 | 8456 (14.2) | 258 (15.9) | 809 (20.8) | 336 (20.7) | ||
| ≥75 | 3506 (5.9) | 131 (8.1) | 458 (11.8) | 196 (12.0) | ||
| Race/ethnicity | ||||||
| White | 47 739 (79.9) | 1436 (88.4) | 3490 (89.7) | 1466 (90.1) | <.001 | .69 |
| African American | 6780 (11.4) | 84 (5.2) | 176 (4.5) | 71 (4.4) | ||
| Hispanic | 2709 (4.5) | 49 (3.0) | 107 (2.7) | 35 (2.2) | ||
| American Indian/Alaska Native | 341 (0.6) | 4 (0.2) | 18 (0.5) | 7 (0.4) | ||
| Asian/Pacific Islander | 1363 (2.3) | 27 (1.7) | 55 (1.4) | 24 (1.5) | ||
| Unknown | 800 (1.3) | 24 (1.5) | 45 (1.2) | 24 (1.5) | ||
| Education | ||||||
| ≤High school/GED | 14 638 (24.5) | 363 (22.4) | 969 (24.9) | 362 (22.2) | .28 | .08 |
| School after high school | 23 468 (39.3) | 621 (38.2) | 1500 (38.6) | 675 (41.5) | ||
| ≥College graduate | 21 208 (35.5) | 631 (38.9) | 1397 (35.9) | 579 (35.6) | ||
| BMI, mean (SD) | 28.9 (6.0) | 27.9 (5.3) | 28.6 (5.7) | 28.2 (5.7) | ||
| <25 | 16 811 (28.1) | 521 (32.1) | 1139 (29.3) | 517 (31.8) | <.001 | <.001 |
| 25 to <30 | 20 978 (35.1) | 613 (37.7) | 1426 (36.6) | 593 (36.4) | ||
| ≥30 | 21 943 (36.7) | 490 (30.2) | 1326 (34.1) | 517 (31.8) | ||
| ≥1 Fall during the past year | ||||||
| Yes | 18 251 (30.6) | 600 (36.9) | 1491 (38.3) | 580 (35.6) | <.001 | .19 |
| No | 41 037 (68.7) | 1011 (62.3) | 2376 (61.1) | 1030 (63.3) | ||
| Unknown | 444 (0.7) | 13 (0.8) | 24 (0.6) | 17 (1.0) | ||
| Fracture at age 55 y or older | ||||||
| Yes | 4903 (8.2) | 219 (13.5) | 613 (15.8) | 284 (17.5) | <.001 | <.001 |
| No | 54 354 (91.0) | 1396 (86.0) | 3249 (83.5) | 1320 (81.1) | ||
| Unknown | 475 (0.8) | 9 (0.6) | 29 (0.7) | 23 (1.4) | ||
| Smoking | ||||||
| Never | 30 424 (50.9) | 802 (49.4) | 1973 (50.7) | 822 (50.5) | .51 | .32 |
| Past | 24 041 (40.2) | 690 (42.5) | 1582 (40.7) | 654 (40.2) | ||
| Current | 4681 (7.8) | 119 (7.3) | 286 (7.4) | 137 (8.4) | ||
| Alcohol drinks/wk, mean (SD) | 2.1 (4.4) | 2.4 (4.4) | 2.4 (5.0) | 2.1 (4.7) | ||
| 0 | 26 261 (44.0) | 655 (40.3) | 1669 (42.9) | 727 (44.7) | <.001 | .13 |
| >0 to <7 | 27 200 (45.5) | 783 (48.2) | 1759 (45.2) | 740 (45.5) | ||
| ≥7 | 6108 (10.2) | 181 (11.1) | 451 (11.6) | 155 (9.5) | ||
| Physical activity (total MET h/wk), mean (SD) | 10.8 (12.8) | 12.0 (12.9) | 10.4 (12.0) | 10.6 (12.6) | ||
| 0 | 11 377 (19.0) | 264 (16.3) | 721 (18.5) | 295 (18.1) | .84 | <.001 |
| >0 to <5 | 14 125 (23.6) | 357 (22.0) | 902 (23.2) | 419 (25.8) | ||
| 5 to <12 | 14 321 (24.0) | 388 (23.9) | 1004 (25.8) | 379 (23.3) | ||
| ≥12 | 19 909 (33.3) | 615 (37.9) | 1264 (32.5) | 534 (32.8) | ||
| Estrogen therapy use (pill or transdermal patch)b | <.001 | .004 | ||||
| Never | 21 140 (35.4) | 642 (39.5) | 1691 (43.5) | 634 (39.0) | <.001 | .004 |
| Past | 8368 (14.0) | 245 (15.1) | 608 (15.6) | 270 (16.6) | ||
| Current | 30 224 (50.6) | 737 (45.4) | 1592 (40.9) | 723 (44.4) | ||
| Calcium intake,c mg/d, mean (SD) | 1132.2 (685.5) | 1182.7 (698.1) | 1145.0 (668.0) | 1176.5 (673.1) | ||
| <400 | 4984 (8.3) | 110 (6.8) | 266 (6.8) | 117 (7.2) | <.001 | .10 |
| 400 to <800 | 16 468 (27.6) | 456 (28.1) | 1119 (28.8) | 411 (25.3) | ||
| 800 to <1200 | 15 003 (25.1) | 384 (23.6) | 978 (25.1) | 419 (25.8) | ||
| ≥1200 | 22 049 (36.9) | 642 (39.5) | 1444 (37.1) | 644 (39.6) | ||
| Vitamin D intake,d IU/d, mean (SD) | 351.6 (266.9) | 359.9 (271.9) | 356.5 (259.2) | 374.9 (264.4) | ||
| <200 | 23 693 (39.7) | 633 (39.0) | 1480 (38.0) | 575 (35.3) | .004 | .06 |
| 200 to <400 | 11 184 (18.7) | 313 (19.3) | 745 (19.1) | 302 (18.6) | ||
| 400 to <600 | 13 643 (22.8) | 353 (21.7) | 907 (23.3) | 401 (24.6) | ||
| ≥600 | 9984 (16.7) | 293 (18.0) | 675 (17.3) | 313 (19.2) | ||
| Physical Function Score,e mean (SD) | 80.7 (19.8) | 82.2 (18.5) | 78.3 (20.6) | 77.1 (21.5) | ||
| ≤60 | 9788 (16.4) | 227 (14.0) | 736 (18.9) | 369 (22.7) | <.001 | <.001 |
| 60 to <90 | 20 402 (34.2) | 555 (34.2) | 1474 (37.9) | 573 (35.2) | ||
| ≥90 | 29 542 (49.5) | 842 (51.8) | 1681 (43.2) | 685 (42.1) | ||
| History of treated diabetes | ||||||
| Yes | 2953 (4.9 | 79 (4.9) | 218 (5.6) | 96 (5.9) | .04 | .04 |
| No | 56 779 (95.1) | 1545 (95.1) | 3673 (94.4) | 1531 (94.1) | ||
| History of cancer | ||||||
| Yes | 2808 (4.7) | 88 (5.4) | 205 (5.3) | 87 (5.3) | .07 | .80 |
| No | 56 593 (94.7) | 1524 (93.8) | 3668 (94.3) | 1531 (94.1) | ||
| WHI component | ||||||
| Clinical trial | 53 603 (89.7) | 1480 (91.1) | 3527 (90.6) | 1447 (88.9) | .10 | NA |
| Observational study | 6129 (10.3 | 144 (8.9) | 364 (9.4) | 180 (11.1) | ||
Abbreviations: BMI, body mass index (calculated as weight in kilograms divided by height in meters squared); GED, general educational developmental certificate; MET, metabolic equivalent task; WHI, Women’s Health Initiative.
a
Fracture sites included lower extremity (ankle, hip, patella, pelvis, shaft of femur, tibia/fibula, tibial plateau), upper extremity (carpal, elbow, lower end of humerus, radius/ulna, upper end of humerus, shaft of humerus, upper radius/ulna), and spine (lumbar spine, thoracic spine) fractures. Individual fracture site columns do not include 89 participants who had initial fractures at multiple body areas.
b
Hormone use incorporates self-report and Women’s Health Initiative Hormone Therapy Trial assignment.
c
From dietary intake and supplement use.
d
From dietary intake and supplement use.
e
RAND 36-item physical function score. Range is 0 to100, in which a higher score indicates a more favorable health state.