Perinatal and early childhood risk factors for rheumatoid factor positivity stratified by HLA DR4 status
| DR4− | DR4+ | |||
|---|---|---|---|---|
| 9 RF+ and 180 RF− children | 14 RF+ and 431 RF− children | |||
| OR (95% CI) | p Value | OR (95% CI)‡ | p Value | |
| RF, rheumatoid factor. | ||||
| *Odds ratio calculated for a 1-year increase in age. | ||||
| †Other includes Hispanic (70.0%), African-American (16.7%), Asian (3.3%) and biracial (10.0%), compared with non-Hispanic white. | ||||
| ‡Race, sex, maternal education, breast feeding duration and other environmental tobacco smoke did not add significantly to the model in DR4 positive children, and were removed. | ||||
| Age* | 0.71 (0.46 to 1.09) | 0.115 | 0.88 (0.71 to 1.10) | 0.259 |
| Other race/ethnicity† | 6.94 (1.10 to 43.88) | 0.039 | ||
| Male | 0.23 (0.04 to 1.41) | 0.112 | ||
| Maternal education ⩽12 years | 4.91 (0.43 to 56.48) | 0.202 | ||
| Breast feeding duration >3 months | 0.18 (0.04 to 0.99) | 0.049 | ||
| Exposure to cigarette smoking by care giver/relative/friend | 5.38 (0.93 to 31.27) | 0.061 | ||