Table 1 Clinical characteristics of the study cohorts
From: Genetic variant in IL33 is associated with susceptibility to rheumatoid arthritis
Discovery population | Validation population | Replication population | |
|---|---|---|---|
Number of cases | 700 | 586 | 666 |
Ethnicity | Northern Han Chinese | Southern Han Chinese | Northern and Southern |
Female, % | 79.9 | 81.2 | 82.8 |
Age, mean ± SD years | 54.0 ± 13.1 | 52.4 ± 13.9 | 54.3 ± 12.8 |
Age at RA onset, mean ± SD years | 46.4 ± 16.0 | 46.3 ± 15.0 | 46.6 ± 15.4 |
Disease duration, mean ± SD years | 8.1 ± 8.1 | 7.8 ± 7.3 | 9.0 ± 10.3 |
ACPA status, % positive | 72.6 | 75.3 | 68.9 |
RF status, % positive | 81.6 | 78.3 | 84.0 |