Results of group A vs group C, and of group A vs group C1 analyses: sensitivity and specificity of the different questions, clinical features and laboratory features included in the anamnestic, clinical and laboratory item, respectively
| Sensitivity (%) | 95% CI (%) | Specificity (%) | 95% CI (%) | |
|---|---|---|---|---|
| Group A vs group C | ||||
| 'At least 2 out of the 3 questions' | 83.8 | 79.4 to 88.2 | 90.6 | 87.8 to 93.4 |
| 'At least 3 out of the 4 features' among constitutional symptoms, articular, vascular or neurological involvement | 70.2 | 64.7 to 75.8 | 68.7 | 64.2 to 73.3 |
| 'At least 2 out of the 3 features' among serum C4 levels, rheumatoid factors (RFs) and serum M component | 84.2 | 79.4 to 89.0 | 97.7 | 95.7 to 99.7 |
| Group A vs group C1 (systemic vasculitis) | ||||
| 'At least 2 out of the 3 questions' | 83.8 | 79.4 to 88.2 | 85.5 | 80.3 to 90.8 |
| 'At least 3 out of the 4 features' among constitutional symptoms, articular, vascular or neurological involvement | 70.2 | 64.7 to 75.8 | 53.0 | 45.4 to 60.7 |
| 'At least 2 out of the 3 features' among serum C4 levels, RFs and serum M component | 84.2 | 79.4 to 89.0 | 100 | |