Table 1. Characteristics of patients with dermatomyositis.
| Characteristic | Training cohort (n = 168) | Validation cohort (n = 72) | ||||
|---|---|---|---|---|---|---|
| N | Percent (%) | N | Percent (%) | P | ||
| Basic information | ||||||
| Age (years), mean ± SD | 48.09 ± 18.69 | 44.43 ± 16.73 | 0.153 | |||
| Sex | 0.977 | |||||
| Male | 65 | 38.7 | 28 | 38.9 | ||
| Female | 103 | 61.3 | 44 | 61.1 | ||
| Clinical manifestation | ||||||
| Gottron’s sign | 0.167 | |||||
| yes | 84 | 50.0 | 43 | 59.7 | ||
| no | 84 | 50.0 | 29 | 40.3 | ||
| Periungual erythema | 0.792 | |||||
| yes | 19 | 11.3 | 9 | 12.5 | ||
| no | 149 | 88.7 | 63 | 87.5 | ||
| Poikiloderma | 0.019 | |||||
| yes | 47 | 28.0 | 10 | 13.9 | ||
| no | 121 | 72.0 | 62 | 86.1 | ||
| Refractory itching | 0.562 | |||||
| yes | 21 | 12.5 | 11 | 15.3 | ||
| no | 147 | 87.5 | 61 | 84.7 | ||
| V-neck sign | 0.842 | |||||
| yes | 70 | 41.7 | 31 | 43.1 | ||
| no | 98 | 58.3 | 41 | 56.9 | ||
| Periorbital erythema | 0.185 | |||||
| yes | 113 | 67.3 | 42 | 58.3 | ||
| no | 55 | 32.7 | 30 | 41.7 | ||
| Raynaud’s phenomenon | 0.778 | |||||
| yes | 8 | 4.8 | 4 | 5.6 | ||
| no | 160 | 95.2 | 67 | 94.4 | ||
| Joint pain | 0.258 | |||||
| yes | 23 | 13.7 | 14 | 19.4 | ||
| no | 145 | 86.3 | 58 | 80.6 | ||
| Proximal muscle weakness | 0.829 | |||||
| yes | 119 | 70.8 | 50 | 69.4 | ||
| no | 49 | 29.2 | 22 | 30.6 | ||
| Dysphagia | 0.837 | |||||
| yes | 37 | 22.0 | 15 | 20.8 | ||
| no | 131 | 78.0 | 57 | 79.2 | ||
| Complication | ||||||
| Malignant tumor | 0.157 | |||||
| yes | 42 | 25.0 | 12 | 16.7 | ||
| no | 126 | 75.5 | 60 | 83.3 | ||
| Interstitial pneumonia | 0.411 | |||||
| yes | 72 | 42.9 | 35 | 48.6 | ||
| no | 96 | 57.1 | 37 | 51.4 | ||
| Respiration failure | 0.205 | |||||
| yes | 30 | 17.9 | 18 | 25.0 | ||
| no | 138 | 82.1 | 54 | 75.0 | ||
| Laboratory values | ||||||
| CK (U/L) | 0.058 | |||||
| ≥198 | 69 | 41.1 | 20 | 27.8 | ||
| <198 | 99 | 58.9 | 52 | 72.2 | ||
| LDH (U/L) | 0.104 | |||||
| ≥300 | 103 | 61.3 | 36 | 50.0 | ||
| <300 | 65 | 38.7 | 36 | 50.0 | ||
| ANA | 0.862 | |||||
| Positive | 103 | 61.3 | 45 | 62.5 | ||
| Negative | 65 | 38.7 | 27 | 37.5 | ||
| Anti-Jo-1 | 0.004 | |||||
| Positive | 4 | 2.4 | 8 | 11.1 | ||
| Negative | 164 | 97.6 | 64 | 88.9 | ||
| CA125 (U/ml) | 0.375 | |||||
| ≥35 | 15 | 8.9 | 4 | 5.6 | ||
| <35 | 153 | 91.1 | 68 | 94.4 | ||
| CA19-9(U/ml) | 0.200 | |||||
| ≥37 | 21 | 12.6 | 5 | 6.9 | ||
| <37 | 146 | 87.4 | 67 | 93.1 | ||
Notes.
- CK
- creatine kinase
- LDH
- lactate dehydrogenase
- ANA
- antinuclear antibody
- CA125
- carbohydrate antigen 125
- CA19-9
- carbohydrate antigen 19-9