TABLE 1.
Clinical characteristics of participants before and after matching.
| Before matching |
After matching |
|||||||
| Total (n = 469) |
SNRA (n = 110) |
SPRA (n = 359) |
p a | Total (n = 312) |
Group A (n = 104) |
Group B (n = 208) |
p a | |
| Age, years | 58 (14) | 55 (14) | 60 (13) | 0.014 | 57 (14) | 55 (14) | 57 (14) | 0.504 |
| Female, n (%) | 398 (84.9) | 96 (87.3) | 302 (84.1) | 0.420 | 275 (88.1) | 90 (86.5) | 185 (88.9) | 0.536 |
| Postmenopause, n (%) | 313 (78.6) | 67 (69.8) | 246 (81.5) | 0.015 | 208 (75.6) | 64 (71.1) | 164 (77.8) | 0.223 |
| BMI, kg/m2 | 23.1 (5.1) | 23.7 (5.0) | 23 (5.1) | 0.155 | 23.4 (5.2) | 23.8 (5.2) | 23.0 (5.4) | 0.123 |
| Comorbidities +, n (%) | 278 (59.3) | 63 (57.3) | 215 (59.9) | 0.625 | 190 (60.9) | 63 (60.6) | 127 (61.1) | 0.935 |
| RA- related factors | ||||||||
| Disease duration, years | 13 (3) | 12 (13) | 13 (13) | 0.870 | 12 (11) | 12 (13) | 12 (12) | 0.765 |
| Baseline DAS28-ESR | 3.2 (1.7) | 2.7 (1.6) | 3.3 (1.6) | <0.001 | 3.0 (1.6) | 2.7 (1.7) | 3.3 (1.5) | 0.002 |
| Mean DAS28-ESR | 3.0 (1.2) | 2.8 (1.2) | 3.0 (1.2) | 0.017 | 2.9 (1.2) | 2.9 (1.2) | 3.0 (1.1) | 0.088 |
| HAQ-DI | 0.25 (0.88) | 0.13 (0.75) | 0.25 (1.0) | 0.092 | 0.25 (0.88) | 0.13 (0.66) | 0.25 (0.88) | 0.295 |
| ESR, mm/h | 17 (21) | 11.0 (13.0) | 18.0 (24.0) | <0.001 | 16 (19) | 11 (13.8) | 17 (20.5) | 0.001 |
| Fracture-related factorsb + | ||||||||
| Parent fractured hip +, n (%) | 36 (7.7) | 10 (9.2) | 26 (7.3) | 0.522 | 26 (8.3) | 10 (9.7) | 16 (7.8) | 0.571 |
| Previous fracture +, n (%) | 148 (31.6) | 36 (32.7) | 112 (31.2) | 0.763 | 100 (32.1) | 34 (32.7) | 66 (31.7) | 0.864 |
| Alcohol +, n (%) | 7 (1.5) | 2 (1.8) | 5 (1.4) | 0.747 | 4 (1.3) | 2 (1.9) | 2 (1.0) | 0.477 |
| Smoking +, n (%) | 31 (6.6) | 4 (3.6) | 27 (7.5) | 0.190 | 15 (4.8) | 4 (3.8) | 11 (5.3) | 0.575 |
| Secondary osteoporosis +, n (%) | 21 (4.5) | 3 (2.7) | 18 (5.0) | 0.432 | 8 (2.6) | 2 (1.9) | 6 (2.9) | 0.612 |
| BMD (g/m2) | ||||||||
| FN | 0.633 ± 0.120 | 0.648 ± 0.122 | 0.620 ± 0.117 | 0.014 | 0.641 ± 0.123 | 0.664 ± 0.114 | 0.627 ± 0.125 | 0.004 |
| TH | 0.789 ± 0.141 | 0.801 ± 0.140 | 0.775 ± 0.142 | 0.067 | 0.796 ± 0.143 | 0.818 ± 0.128 | 0.784 ± 0.147 | 0.015 |
| L1–4 | 0.871 ± 0.170 | 0.885 ± 0.167 | 0.860 ± 0.168 | 0.129 | 0.874 ± 0.868 | 0.894 ± 0.167 | 0.863 ± 0.163 | 0.104 |
| Osteoporosisc, n (%) | 138 (29.4) | 22 (16.2) | 116 (24.9) | 0.033 | 81 (26) | 16 (15.4) | 65 (31.3) | 0.003 |
| FRAX score | ||||||||
| Major | 14 (18.9) | 12 (13.5) | 15 (19) | 0.007 | 13 (18.1) | 12 (13.9) | 14 (20.2) | 0.086 |
| Hip | 4.2 (8.4) | 3.4 (6.2) | 5.0 (9.5) | 0.001 | 3.9 (8) | 3.4 (6.1) | 4.3 (9.5) | 0.018 |
| New incident fracture (3 years), n (%) | 132 (28.1) | 24 (26.1) | 108 (34.8) | 0.116 | 86 (27.6) | 22 (25.3) | 64 (36) | 0.082 |
| Medications | ||||||||
| GC +, n (%) | 409 (87.2) | 90 (81.8) | 319 (88.9) | 0.053 | 291 (93.3) | 92 (88.5) | 199 (95.7) | 0.017 |
| b/tsDMARDsd + n (%) | 84 (17.9) | 12 (10.9) | 72 (20.1) | 0.031 | 79 (25.3) | 16 (15.4) | 63 (30.3) | 0.004 |
| AOTe +, n (%) | 163 (34.8) | 30 (27.3) | 133 (37) | 0.060 | 134 (42.9) | 42 (40.4) | 92 (42.4) | 0.518 |
| BP +, n (%) | 143 (87.7) | 25 (83.37) | 118 (88.7) | 0.617 | 115 (85.8) | 31 (73.8) | 84 (91.3) | 0.015 |
| RANKLi +, n (%) | 14 (8.6) | 3 (10) | 11 (8.3) | 0.764 | 7 (5.2) | 3 (7.1) | 4 (4.3) | 0.791 |
Values are presented as mean ± standard deviation or median (interquartile range), unless otherwise mentioned. SNRA, seronegative rheumatoid arthritis; SPRA, seropositive rheumatoid arthritis; BMI, body mass index; DAS28-ESR, disease activity score-28 joint-erythrocyte sedimentation; HAQ-DI, health assessment questionnaire disability index; ESR, erythrocyte sedimentation rate; BMD, bone mineral density; FN, femoral neck; TH, total hip; L1–4, 1st–4th lumbar vertebra; FRAX, fracture risk assessment tool; GC, glucocorticoid; b/tsDMARDs, biologic/target synthetic disease modify anti-rheumatic drugs; AOT, Anti-osteoporotic therapy; BP, bisphosphonate; RANKLi, Receptor activator of nuclear factor-kB ligand inhibitor (denosumab).
+, presence.
aComparison between seronegative and seropositive groups.
bDefined as in FRAX tool.
cT-score (femoral neck) ≤ −2.5.
dIncluding anti-TNFa (etanercept, adalimumab, golimumab, certolizumab), anti-IL6 receptor (tocilizumab), CTLA4 analog (abatacept), anti-CD 20 (rituximab), and JAK inhibitor, (tofacitinib).
eIncluding bisphosphonates, denosumab, teriparatide, and raloxifene during observation period.