Simple and multivariable linear regression with number of ACPA reactivities positive (anti-CCP2 antibodies excluded) as dependent variable
| Simple | Multivariable* | Multivariable† | Multivariable‡ | |||||||||
| β value | 95% CI | P value | β value | 95% CI | P value | β value | 95% CI | P value | β value | 95% CI | P value | |
| Ever Smoker+/− | 2.11 | 1.26 to 3.00 | <0.000§ | 1.18 | 0.45 to 1.91 | 0.002 | 1.75 | 0.80 to 2.71 | <0.001 | 2.29 | 1.25 to 3.33 | <0.001 |
| HLA-SE+/− | 3.55 | 2.74 to 4.36 | <0.000§ | 0.98 | 0.26 to 1.69 | 0.007 | 2.63 | 1.72 to 3.55 | <0.001 | 3.46 | 2.48 to 4.45 | <0.001 |
| RF+/− | 7.24 | 6.42 to 8.06 | <0.000§ | – | – | – | 5.77 | 4.74 to 6.80 | <0.001 | – | – | – |
| Anti-CCP2+/− | 10.60 | 9.98 to 11.14 | <0.000§ | 10.11 | 9.34 to 10.89 | <0.001 | – | – | – | – | – | – |
| PTPN22 1858 T-carriage+/− | 1.23 | 0.18 to 2.29 | 0.022 | 0.57 | 0.17 to 1.30 | 0.129 | 1.01 | 0.05 to 1.97 | 0.039 | 1.09 | 0.05 to 2.14 | 0.041 |
| BMI, m2/kg | 0.10 | −0.01 to 0.21 | 0.073 | 0.10 | 0.01 to 0.17 | 0.023 | 0.08 | −0.02 to 0.19 | 0.129 | 0.09 | −0.03 to 0.21 | 0.124 |
| DAS28-AUC | 0.03 | 0.01 to 0.04 | 0.010 | 0.02 | 0.00 to 0.03 | 0.036 | 0.02 | 0.00 to 0.04 | 0.024 | 0.03 | 0.01 to 0.05 | 0.009 |
Adjusted for sex and age at disease onset.
*Analyses including all factors from simple analysis except for RF status, multivariable.
†Analyses including all factors from simple analysis except for anti-CCP2 antibody status, multivariable.
‡Analyses including all factors from simple analysis except for RF and anti-CCP2 antibody status, multivariable.
§Indicates p value remaining significant after correction for number of performed tests.
ACPA, anticitrullinated peptide/protein antibody; anti-CCP2, anticyclic citrullinated peptide antibodies; BMI, body mass index; DAS28-AUC, area under curve for 28-joint disease activity score during 24 months; HLA-SE, human leucocyte antigen-shared epitope; PTPN22, protein tyrosine phosphatase non-receptor type 22; RF, rheumatoid factor.