Table 1. Baseline Characteristics of Study Patients.
| Characteristic | Total (N = 328 080) | RA status | Serologic status of RA | ||||||
|---|---|---|---|---|---|---|---|---|---|
| No (n = 273 400) | Yes (n = 54 680) | P value | SMD | SNRA (n = 15 670) | SPRA (n = 39 010) | P value | SMD | ||
| Age, mean (SD), y | 58.6 (10.1) | 58.6 (10.1) | 58.6 (10.1) | >.99 | 0 | 57.8 (10.0) | 58.9 (10.1) | <.001 | .114 |
| 40-64 | 233 166 (71.1) | 194 305 (71.1) | 38 861 (71.1) | 11 629 (74.2) | 27 232 (69.8) | ||||
| ≥65 | 94 914 (28.9) | 79 095 (28.9) | 15 819 (28.9) | 4041 (25.8) | 11 778 (30.2) | ||||
| Sex | |||||||||
| Male | 82 404 (25.1) | 68 670 (25.1) | 13 734 (25.1) | >.99 | 0 | 4189 (26.7) | 9545 (24.5) | <.001 | .052 |
| Female | 245 676 (74.9) | 20 4730 (74.9) | 40 946 (74.9) | 11 481 (73.3) | 29 465 (75.5) | ||||
| Income | |||||||||
| <25% + Medicaid group | 76 983 (23.5) | 64 191 (23.5) | 12 792 (23.4) | .67 | .002 | 12 161 (77.6) | 29 727 (76.2) | <.001 | .033 |
| >25% | 251 097 (76.5) | 209 209 (76.5) | 41 888 (76.6) | 3509 (22.4) | 9283 (23.8) | ||||
| Smoking status | |||||||||
| Never-smoker | 260 705 (79.5) | 217 978 (79.7) | 42 727 (78.1) | <.001 | .039 | 12 198 (77.8) | 30 529 (78.3) | <.001 | .010 |
| Ex-smoker + <20 pack-y | 18 910 (5.8) | 15 676 (5.7) | 3234 (5.9) | .008 | 1161 (7.4) | 2073 (5.31) | .086 | ||
| Ex-smoker + ≥20 pack-y | 13 298 (4.1) | 10 613 (3.9) | 2685 (4.9) | .050 | 824 (5.3) | 1861 (4.8) | .022 | ||
| Current smoker + <20 pack-y | 17 404 (5.3) | 14 633 (5.4) | 2771 (5.1) | .013 | 772 (4.9) | 1999 (5.1) | .009 | ||
| Current smoker + ≥20 pack-y | 17 763 (5.4) | 14 500 (5.3) | 3263 (6.0) | .029 | 715 (4.6) | 2548 (6.5) | .086 | ||
| Alcohol consumption | |||||||||
| None | 235 686 (71.8) | 193 905 (70.9) | 41 781 (76.4) | <.001 | .125 | 11 755 (75.0) | 30 026 (77.0) | <.001 | .046 |
| Mild (<30 g/d) | 81 076 (24.7) | 69 654 (25.5) | 11 422 (20.9) | .109 | 3454 (22.0) | 7968 (20.4) | .040 | ||
| Heavy (≥30 g/d) | 11 318 (3.5) | 9841 (3.6) | 1477 (2.7) | .051 | 461 (2.9) | 1016 (2.6) | .021 | ||
| Physical activity | |||||||||
| None | 261 247 (79.6) | 216 594 (79.2) | 44 653 (81.7) | <.001 | .062 | 12 588 (80.3) | 32 065 (82.2) | <.001 | .048 |
| Regular | 66 833 (20.4) | 56 806 (20.8) | 10 027 (18.3) | 3082 (19.7) | 6945 (17.8) | ||||
| Body mass indexa | |||||||||
| <18.5 | 9324 (2.8) | 7237 (2.7) | 2087 (3.8) | <.001 | .066 | 517 (3.3) | 1570 (4.0) | <.001 | NA |
| 18.5-22.9 | 127 102 (38.7) | 104 475 (38.2) | 22 627 (41.4) | .065 | 6145 (39.2) | 16 482 (42.3) | |||
| 23.0-24.9 | 83 076 (25.3) | 69 736 (25.5) | 13 340 (24.4) | .026 | 3844 (24.5) | 9496 (24.3) | |||
| 25.0-29.9 | 95 980 (29.3) | 81 260 (29.7) | 14 720 (26.9) | .062 | 4501 (28.7) | 10 219 (26.2) | |||
| ≥30.0 | 12 598 (3.8) | 10 692 (3.9) | 1906 (3.5) | .023 | 663 (4.2) | 1243 (3.2) | |||
| Diabetes | 43 809 (13.4) | 36 418 (13.3) | 7391 (13.5) | .218 | .006 | 2251 (14.4) | 5140 (13.2) | <.001 | .039 |
| Hypertension | 128 345 (39.1) | 105 349 (38.5) | 22 996 (42.1) | <.001 | .072 | 6984 (44.6) | 16 012 (41.1) | <.001 | .062 |
| Dyslipidemia | 109 338 (33.3) | 90 641 (33.2) | 18 697 (34.2) | <.001 | .022 | 5869 (37.5) | 12 828 (32.9) | <.001 | .004 |
| Chronic kidney disease | 23 184 (7.1) | 18 465 (6.9) | 4719 (8.6) | <.001 | .070 | 1501 (9.6) | 3218 (8.3) | <.001 | .057 |
| Myocardial infarction | 2101 (0.6) | 1490 (0.5) | 611 (1.1) | <.001 | .063 | 189 (1.2) | 422 (1.1) | .21 | .055 |
| Stroke | 1935 (0.6) | 1422 (0.5) | 513 (0.9) | <.001 | .049 | 162 (1.0) | 351 (0.9) | .14 | .035 |
| Depression | 23 804 (7.3) | 16 111 (5.9) | 7693 (14.1) | <.001 | .275 | 2429 (15.5) | 5264 (13.5) | <.001 | .071 |
Abbreviations: NA, not applicable; SMD, standardized mean difference; SNRA, seronegative rheumatoid arthritis; SPRA, seropositive rheumatoid arthritis.
a
Measured as weight in kilograms divided by height in meters squared.