Table 1. Characteristics of Study Participants at Baseline Overall and by Major Osteoporotic Fracture Event.
| Baseline characteristic | Participant groupa | P valueb | ||
|---|---|---|---|---|
| All (n = 67 169) | MOF event | |||
| No (n = 61 575) | Yes (n = 5594) | |||
| Age, mean (SD), y | 57.8 (4.1) | 57.8 (4.1) | 58.6 (4.0) | <.001 |
| Self-reported race and ethnicity | ||||
| Asian | 1486 (2.2) | 1407 (2.3) | 79 (1.4) | <.001 |
| Black | 5927 (8.8) | 5652 (9.2) | 275 (4.9) | |
| Hispanic | 2545 (3.8) | 2341 (3.8) | 204 (3.6) | |
| White | 57 211 (85.2) | 52 175 (84.7) | 5036 (90.0) | |
| BMI | ||||
| Mean (SD) | 28.0 (6.1) | 28.0 (6.1) | 28.2 (6.1) | |
| <25 | 23 759 (35.4) | 21 858 (35.5) | 1901 (34.0) | .09 |
| 25 to <30 | 22 666 (33.7) | 20 732 (33.7) | 1934 (34.6) | |
| ≥30 | 20 396 (30.4) | 18 669 (30.3) | 1727 (30.9) | |
| Physical function score, mean (SD)c | 85.3 (17.7) | 85.6 (17.4) | 81.9 (20.5) | <.001 |
| Smoking | ||||
| Never | 32 880 (49.0) | 30 308 (49.2) | 2572 (46.0) | <.001 |
| Past | 28 669 (42.7) | 26 228 (42.6) | 2441 (43.6) | |
| Current | 4962 (7.4) | 4456 (7.2) | 506 (9.0) | |
| Alcohol intake | ||||
| Never | 5790 (8.6) | 5260 (8.5) | 530 (9.5) | <.001 |
| Past | 11 055 (16.5) | 10 033 (16.3) | 1022 (18.3) | |
| Current (≥1 drink/mo) | 49 941 (74.4) | 45 940 (74.6) | 4001 (71.5) | |
| Menopausal HT used | 37 476 (55.8) | 34 792 (56.5) | 2684 (48.0) | <.001 |
| Daily oral glucocorticoid usee | 193 (0.3) | 157 (0.3) | 36 (0.6) | <.001 |
| Falls in the past year | ||||
| 0 | 42 652 (63.5) | 39 498 (64.1) | 3154 (56.4) | <.001 |
| 1 | 12 762 (19.0) | 11 543 (18.7) | 1219 (21.8) | |
| 2 | 5320 (7.9) | 4755 (7.7) | 565 (10.1) | |
| ≥3 | 2821 (4.2) | 2424 (3.9) | 397 (7.1) | |
| History of fracture aged ≥55 y | ||||
| Yes | 2808 (4.2) | 2356 (3.8) | 452 (8.1) | <.001 |
| No | 45 146 (67.2) | 41 270 (67.0) | 3876 (69.3) | |
| Not applicable (aged <55 y) | 16 049 (23.9) | 15 044 (24.4) | 1005 (18.0) | |
| Parental history of hip fracture | 7706 (11.5) | 6900 (11.2) | 806 (14.4) | <.001 |
| Early menopause (aged <45 y) | 13 457 (20.0) | 12 287 (20.0) | 1170 (20.9) | .009 |
| History of rheumatoid arthritis | 2478 (3.7) | 2183 (3.5) | 295 (5.3) | <.001 |
| History of malabsorptionf | 193 (0.3) | 169 (0.3) | 24 (0.4) | .12 |
| History of liver disease | 1523 (2.3) | 1361 (2.2) | 162 (2.9) | .004 |
| History of emphysema | 1721 (2.6) | 1503 (2.4) | 218 (3.9) | <.001 |
| FRAX-estimated 10-y risk of MOF | ||||
| Mean (SD), % | 7.1 (4.1) | 7.0 (4.0) | 8.2 (4.9) | |
| <8.4% | 51 638 (76.9) | 47 847 (77.7) | 3791 (67.8) | <.001 |
| ≥8.4% | 15 531 (23.1) | 13 728 (22.3) | 1803 (32.2) | |
| OST scoreg | ||||
| Mean (SD) | 3.0 (3.4) | 3.0 (3.4) | 3.0 (3.4) | |
| <2 | 26 201 (39.0) | 23 991 (39.0) | 2210 (39.5) | .54 |
| ≥2 | 40 968 (61.0) | 37 584 (61.0) | 3384 (60.5) | |
Abbreviations: BMI, body mass index (calculated as weight in kilograms divided by height in meters squared; FRAX, Fracture Risk Assessment Tool; HT, hormone therapy; MOF, major osteoporotic fracture; OST, Osteoporosis Screening Tool.
Unless otherwise indicated, data are expressed as No. (%) of participants. Data were missing for body mass index (n = 348), physical function (n = 838), smoking (n = 658), alcohol intake (n = 383), falls in past year (n = 3614), history of fracture at 55 years or older (n = 3166), parental history of hip fracture (n = 2683), early menopause (n = 3651), rheumatoid arthritis (n = 2179), malabsorption (n = 2471), liver disease (n = 2), and emphysema (n = 5061).
Compares characteristic by MOF event status using t tests for continuous variables and χ2 tests for categorical variables.
Calculated using the RAND 36-item Short-Form Health Survey Physical Functioning construct. Scores range from 0 to 100, with higher scores indicating a more favorable health state.
Incorporates both a participant’s self-reported use at baseline as well as her intervention assignment in the Women’s Health Initiative Hormone Therapy Trial. Women assigned to active hormone therapy intervention were characterized as “yes” for hormone therapy use, while women assigned to placebo were categorized at “no.” Women not participating in the Hormone Therapy Trial were assigned their baseline self-report of hormone therapy use (yes, no).
Defined as at least 3 months of use of oral daily use of 5 mg or more of prednisone or equivalent.
Defined as self-report of special diet prescribed for malabsorption, celiac sprue, ulcerative colitis, or Crohn disease.
Calculated as 0.2 × body weight in kilograms − age in years.