Table 5.
Univariate logistic regression for persistent arthritis with anti-CCP/IgM RF as categorical (grouped) variables according to level
| Anti-CCP (units/ml) | OR (95% C.I.) | P | LR+ | LR- | Persistent arthritis patients/patients in category n/N |
|---|---|---|---|---|---|
| ≤ 25 | 1.0 | ref | ref | 122/314 (38.9%) | |
| >25 to 100 | 4.4 (1.6 to 12.5) | 0.005 | 4.1 (1.5 to 11.0) | 0.9 (0.9 to 1.0) | 14/19 (73.7%) |
| >100 to 250 | 9.4 (2.1 to 42.9) | 0.004 | 8.7 (2.0 to 38.2) | 0.9 (0.8 to 1.0) | 12/14 (85.7%) |
| >250 | 13.6 (4.0 to 46.0) | <0.001 | 11.4 (3.5 to 37.0) | 0.8 (0.8 to 0.9) | 26/29 (89.7%) |
| IgM RF (units/ml) | OR (95% C.I.) | P | LR+ | LR- | |
| ≤ 25 | 1.0 | ref | ref | 125/317 (39.4%) | |
| >25 to 75 | 4.6 (2.0 to 10.6) | <0.001 | 4.0 (1.9 to 8.7) | 0.9 (0.8 to 0.9) | 24/32 (75.0%) |
| >75 | 19.2 (4.5 to 82.5) | <0.001 | 16.2 (3.9 to 67.2) | 0.8 (0.8 to 0.9) | 25/27 (92.6%) |
CI: confidence interval; LR+: positive likelihood ratio; LR-: negative likelihood ratio; OR, odds ratio