Baseline characteristics of participants stratified by prevalent/incident osteoporosis status
| Variables | Total N=391 298 | Prevalent osteoporosis at baseline (n=11 875) | Incident osteoporosis during follow-up (n=9307) |
| Age (years), mean (SD) | 56.2 (8.1) | 60.7 (6.6) | 60.5 (6.4) |
| Gender, n (%) | |||
| Female | 207 299 (53.0%) | 8902 (75.0%) | 7617 (81.8%) |
| Ethnicity, n (%) | |||
| White ethnicity | 358 626 (91.7%) | 10 787 (90.8%) | 8567 (92.0%) |
| Mixed ethnicity | 13 732 (3.5%) | 520 (4.4%) | 356 (3.8%) |
| Asian ethnicity | 13 383 (3.4%) | 422 (3.6%) | 290 (3.1%) |
| Black ethnicity | 1777 (0.5%) | 45 (0.4%) | 28 (0.3%) |
| Chinese ethnicity | 1075 (0.3%) | 17 (0.1%) | 14 (0.2%) |
| Other ethnicity | 2705 (0.7%) | 84 (0.7%) | 52 (0.6%) |
| Education level, n (%) | |||
| College or university degree | 138 716 (35.5%) | 3546 (29.9%) | 2831 (30.4%) |
| A levels/AS levels | 46 215 (11.8%) | 1244 (10.5%) | 982 (10.6%) |
| O levels/GCSEs | 83 923 (21.4%) | 2642 (22.2%) | 1992 (21.4%) |
| CSEs | 20 942 (5.4%) | 437 (3.7%) | 353 (3.8%) |
| NVQ or HND or HNC | 25 655 (6.6%) | 649 (5.5%) | 496 (5.3%) |
| Other qualifications | 19 981 (5.1%) | 776 (6.5%) | 601 (6.5%) |
| None of these above | 138 716 (35.5%) | 3546 (29.9%) | 2831 (30.4%) |
| Annual household income, n (%) | |||
| <£18 000 | 85 104 (21.7%) | 4366 (36.8%) | 3298 (35.4%) |
| £18 000–30 999 | 99 321 (25.4%) | 3485 (29.3%) | 2711 (29.1%) |
| £31 000–51 999 | 103 538 (26.5%) | 2354 (19.8%) | 1928 (20.7%) |
| £52 000–100 000 | 81 652 (20.9%) | 1333 (11.2%) | 1101 (11.8%) |
| ≥£100 000 | 21 683 (5.5%) | 337 (2.8%) | 269 (2.9%) |
| Employment status, n (%) | |||
| Employed | 239 333 (61.2%) | 4336 (36.5%) | 3642 (39.1%) |
| Retired | 123 128 (31.5%) | 6331 (53.3%) | 4829 (51.9%) |
| Unemployed | 28 837 (7.4%) | 1208 (10.2%) | 836 (9.0%) |
| Residential area, n (%) | |||
| Urban | 308 469 (78.8%) | 9481 (79.8%) | 7367 (79.2%) |
| Smoking status, n (%) | |||
| Never | 213 830 (54.6%) | 6036 (50.8%) | 4868 (52.3%) |
| Former | 137 326 (35.1%) | 4320 (36.4%) | 3434 (36.9%) |
| Current | 40 142 (10.3%) | 1519 (12.8%) | 1005 (10.8%) |
| Alcohol consumption, n (%) | |||
| Never | 14 309 (3.7%) | 704 (5.9%) | 531 (5.7%) |
| Former | 13 068 (3.3%) | 627 (5.3%) | 478 (5.1%) |
| Current | 363 921 (93.0%) | 10 544 (88.8%) | 8298 (89.2%) |
| Healthy diet score, n (%) | |||
| 0 | 3584 (0.9%) | 81 (0.7%) | 49 (0.5%) |
| 1 | 17 341 (4.4%) | 391 (3.3%) | 310 (3.3%) |
| 2 | 43 237 (11.0%) | 1114 (9.4%) | 828 (8.9%) |
| 3 | 75 402 (19.3%) | 1990 (16.8%) | 1557 (16.7%) |
| 4 | 98 950 (25.3%) | 2896 (24.4%) | 2269 (24.4%) |
| 5 | 94 034 (24.0%) | 3178 (26.8%) | 2519 (27.1%) |
| 6 | 51 893 (13.3%) | 1951 (16.4%) | 1565 (16.8%) |
| 7 | 6857 (1.8%) | 274 (2.3%) | 210 (2.3%) |
| PM2.5 (μg/m3), mean (SD) | 10.0 (1.1) | 10.0 (1.1) | 10.1 (1.1) |
| Physical activity, n (%) | |||
| Not regular | 101 822 (26.9%) | 3619 (32.3%) | 2704 (30.8%) |
| Neuroticism score, mean (SD) | 4.1 (3.2) | 4.5 (3.3) | 4.6 (3.3) |
| NDVI300m, mean (SD) | 0.572 (0.108) | 0.565 (0.110) | 0.569 (0.109) |
| Heel eBMD (g/cm2), mean (SD) | 0.547 (0.139) | 0.371 (0.144) | 0.464 (0.109) |
| BMD T-score, mean (SD) | −0.295 (1.246) | −1.862 (1.311) | −1.008 (1.010) |
Continues variables are displayed as means (SD), and categorical variables are displayed as numbers (percentages).
CSE, Certificate of Secondary Education; eBMD, estimated bone mineral density; GCSE, General Certificate of Secondary Education; HNC, higher national certificate; HND, higher national diploma; NVQ, national vocational qualification; PM2.5, particular matter with aerodynamic diameter ≤2.5 mm.