Demographic and other cohort characteristics.
| National Estimates* | Entire Cohort, n = 4,116,485* | No SSc, n = 4,113,813* | SSc, n = 2672* |
|---|---|---|---|
| Age, yrs, mean (SE); median | 65.2 (0.04); 65.9 | 65.5 (0.04); 66.0 | 63.6 (0.54); 64.5 |
| Age category, yrs | |||
| < 50 | 449,642 (10.9) | 449,321 (10.9) | 321 (12.0) |
| 50–64 | 1,364,821 (33.2) | 1,363,891 (33.2) | 930 (34.8) |
| 65–79 | 1,732,014 (42.1) | 1,730,790 (42.1) | 1224 (45.8) |
| ≥ 80 | 566,521 (13.8) | 566,324 (13.8) | 197 (7.4) |
| Sex | |||
| Female | 2,330,188 (56.6) | 2,327,919 (56.6) | 2269 (84.9) |
| Male | 1,776,722 (43.2) | 1,776,320 (43.2) | 402 (15.1) |
| Race | |||
| White | 2,882,041 (70.0) | 2,880,179 (70.0) | 1862 (69.7) |
| Black | 225,772 (5.5) | 225,583 (5.5) | 189 (7.1) |
| Hispanic | 104,385 (2.5) | 104,255 (2.5) | 130 (4.9) |
| Other/missing | 904,234 (22.0) | 903,743 (22.0) | 491 (18.4) |
| Deyo-Charlson Score | |||
| 0 | 2,193,575 (53.3) | 2,193,575 (53.3) | 0 (0.0) |
| 1 | 926,287 (22.5) | 924,825 (22.5) | 1462 (54.7) |
| ≥ 2 | 996,624 (24.2) | 995,414 (24.2) | 1210 (45.3) |
| Primary diagnosis | |||
| RA | 29,174 (0.7) | 29,099 (0.7) | 75 (2.8) |
| Avascular bone necrosis | 285,622 (6.9) | 285,200 (6.9) | 422 (15.8) |
| Osteoarthritis | 3,447,224 (83.7) | 3,445,373 (83.8) | 1851 (69.3) |
| Other | 354,307 (8.6) | 353,984 (8.6) | 323 (12.1) |
| Fracture | 117 (0.0) | 117 (0.0) | 0 (0.0) |
| Insurance | |||
| Medicaid | 138,809 (3.4) | 138,727 (3.4) | 82 (3.1) |
| Medicare | 2,234,674 (54.3) | 2,233,071 (54.3) | 1603 (60.0) |
| Other | 102,276 (2.5) | 102,246 (2.5) | 30 (1.1) |
| Private | 1,600,830 (38.9) | 1,599,902 (38.9) | 928 (34.7) |
| Self | 32,307 (0.8) | 32,293 (0.8) | 14 (0.5) |
| Income category | |||
| 0–25th percentile | 653,243 (15.9) | 652,828 (15.9) | 415 (15.5) |
| 25th–50th percentile | 1,009,677 (24.5) | 1,009,042 (24.5) | 635 (23.8) |
| 50th–75th percentile | 1,086,953 (26.4) | 1,086,239 (26.4) | 714 (26.7) |
| 75th–100th percentile | 1,285,855 (31.2) | 1,284,984 (31.2) | 871 (32.6) |
| Hospital location/teaching | |||
| Rural | 444,188 (10.8) | 444,031 (10.8) | 157 (5.9) |
| Urban | 1,722,390 (41.8) | 1,721,393 (41.8) | 997 (37.3) |
| Urban teaching | 1,939,988 (47.1) | 1,938,471 (47.1) | 1517 (56.8) |
| Hospital bed size | |||
| Small | 685,209 (16.6) | 684,783 (16.6) | 426 (15.9) |
| Medium | 1,037,562 (25.2) | 1,036,856 (25.2) | 706 (26.4) |
| Large | 2,383,797 (57.9) | 2,382,257 (57.9) | 1540 (57.6) |
| Hospital region | |||
| Northeast | 818,699 (19.9) | 818,058 (19.9) | 641 (24.0) |
| Midwest | 1,089,883 (26.5) | 1,089,259 (26.5) | 624 (23.4) |
| South | 1,358,856 (33.0) | 1,357,985 (33.0) | 871 (32.6) |
| West | 849,045 (20.6) | 848,511 (20.6) | 534 (20.0) |