Table 1.
Demographic and clinical variables of APS patients at baseline.
| Variable | All cases (n = 478) | Training set (n = 239) | Validation set (n = 239) | P-value |
|---|---|---|---|---|
| Male, n (%) | 112 (23.4) | 61 (25.5) | 51 (21.3) | 0.28 |
| Age (years), median (IQR) | 41.0 (31.0-57.0) | 42.0 (32.0-57.0) | 41 (31-57) | 0.94 |
| BMI (kg/m²), median (IQR) | 23.6 (20.8-26.4) | 23.7 (20.7-26.6) | 23.6 (21.0-26.1) | 0.71 |
| Time from the first APS event (months), median (IQR) | 11.0 (1.0-36.0) | 8.0 (1.0-36.0) | 8.0 (1.0-36.0) | 0.71 |
| aGAPSS, median (IQR) | 10.0 (7.0-13.0) | 11.0 (7.0-13.0) | 10.0 (7.0-14.0) | 0.99 |
| Autoimmune disease, n (%) | 216 (45.2) | 115 (48.1) | 101 (42.3) | 0.20 |
| Systemic lupus erythematosus, n (%) | 152 (31.8) | 80 (33.5) | 72 (30.1) | 0.432 |
| Sjögren’s syndrome, n (%) | 34 (7.1) | 15 (6.3) | 19 (7.9) | 0.477 |
| rheumatoid arthritis, n (%) | 19 (4.0) | 12 (5.0) | 7 (2.9) | 0.242 |
| systemic sclerosis, n (%) | 11 (2.3) | 6 (2.5) | 5 (2.1) | 0.760 |
| Vascular thrombosis only, n (%) | 299 (62.6) | 156 (65.3) | 143 (59.8) | 0.22 |
| Pregnancy morbidity only, n (%) | 144 (30.1) | 70 (29.3) | 74 (30.9) | 0.69 |
| Vascular thrombosis and pregnancy morbidity, n (%) | 35 (7.3) | 19 (7.9) | 16 (6.7) | 0.60 |
| Smoking, n (%) | 58 (12.1) | 29 (12.1) | 29 (12.1) | 1.00 |
| Hypertension, n (%) | 135 (28.2) | 74 (31.0) | 61 (25.5) | 0.20 |
| Hyperlipidemia, n (%) | 248 (51.9) | 130 (54.4) | 118 (49.4) | 0.27 |
| Diabetes, n (%) | 66 (13.8) | 37 (15.5) | 29 (12.1) | 0.29 |
| COPD, n (%) | 6 (1.3) | 4 (1.7) | 2 (0.8) | 0.69 |
| Chronic kidney disease, n (%) | 29 (6.1) | 16 (6.7) | 13 (5.4) | 0.57 |
| Hyperuricemia, n (%) | 46 (9.6) | 25 (10.5) | 21 (8.8) | 0.54 |
| Anticoagulation, n (%) | 184 (38.5) | 95 (39.7) | 89 (37.2) | 0.57 |
| Antiplatelet, n (%) | 133 (27.8) | 65 (27.2) | 68 (28.5) | 0.71 |
| Immunosuppressant, n (%) | 203 (42.5) | 111 (46.4) | 92 (38.5) | 0.13 |
| HCQ, n (%) | 229 (47.9) | 113 (47.3) | 116 (48.5) | 0.78 |
| aCL, n (%) | 299 (62.6) | 149 (62.3) | 150 (62.8) | 0.93 |
| aβ2GPI, n (%) | 308 (64.4) | 152 (63.6) | 156 (65.3) | 0.70 |
| LAC, n (%) | 281 (58.8) | 142 (59.4) | 139 (58.2) | 0.78 |
| Triple aPL positivity, n (%) | 165 (34.5) | 75 (31.4) | 90 (37.6) | 0.15 |
| Platelet (×109/L), median (IQR) | 151.0 (76.5-217.0) | 153.0 (87.0-225.0) | 155.0 (66.1-217.0) | 0.31 |
| Mean platelet volume (fl), median (IQR) | 9.8 (8.6-10.9) | 9.8 (8.6-10.9) | 9.8 (8.6-10.9) | 0.71 |
| INR, median (IQR) | 1.0 (0.9-1.1) | 1.0 (0.9-1.2) | 1.0 (0.9-1.2) | 0.28 |
| D-Dimer (ng/ml), median (IQR), | 267.0 (100.0-580.0) | 251.0 (94.0-564.0) | 222.0 (92.0-544.0) | 0.58 |
| ESR increased, n (%) | 203 (42.5) | 98 (41.0) | 105 (43.9) | 0.52 |
| CRP increased, n (%) | 142 (29.7) | 72 (30.1) | 70 (29.3) | 0.84 |
| Low C3, n (%) | 189 (39.5) | 99 (41.4) | 90 (37.7) | 0.40 |
| Low C4, n (%) | 185 (38.7) | 95 (39.7) | 90 (37.7) | 0.64 |
| ANA positive, n (%) | 279 (58.4) | 146 (61.1) | 133 (55.6) | 0.23 |
IS, ischemic stroke; APS, antiphospholipid antibody syndrome; BMI, body mass index; IQR, interquartile range; aGAPSS, adjusted Global Anti-Phospholipid Syndrome Score; COPD, chronic obstructive pulmonary disease; HCQ, Hydroxychloroquine; LAC, lupus anticoagulant; aCL, anti-cardiolipin antibody; aβ2GPI, anti-β2-glycoprotein I antibody; aPL, antiphospholipid antibody; IQR, interquartile range; INR, international normalized ratio; C3, complement 3; C4, complement 4; ANA, antinuclear antibody.