Table 4 Relative odds* (ORs), with 95% confidence intervals (CIs), of rheumatoid factor positive rheumatoid arthritis between tertiles ratios of citrulline/arginine containing C/A (I) C-telopeptide antibody ratios in tertiles* of anti-CCP antibodies
Anti-CCPC/A (I) ratio
LowerMediumHigher
n†OR (95% CI)n†OR (95% CI)n†OR (95% CI)
Lower4/251.003/251.05 (0.18 to 6.01)8/214.26 (0.92 to 19.69)
Medium3/260.79 (0.12 to 5.25)8/175.58 (1.09 to 28.62)15/377.69 (1.61 to 36.87)
Higher8/272.26 (0.41 to 12.59)6/332.58 (0.47 to 14.10)27/2813.71 (2.98 to 63.16)
  • *The tertiles are based on the distributions among controls; †n = number of cases/controls.

  • p value for interaction = 0.28.