Frequency of HLA-DRB1*04 RA linked alleles (0401, 0404, 0405, 0408) and DRB1*01 RA linked alleles (0101, 0102) in young onset rheumatoid arthritis (YORA) and elderly onset rheumatoid arthritis (EORA) subsets. Results are shown as No (%)
| YORA (n=262) | EORA (n=60) |
Odd ratio (95% CI) | |
| DRB1*04 | 135 (52) | 22 (37) | 2.0 (1.0 to 3.3) |
| DRB1*01 | 78 (30) | 22 (37) | 0.7 (0.4 to 1.3) |
| DRB1*01 or 04 | 195 (74) | 43 (72) | 1.1 (0.6 to 2.1) |