Table 5

Adjusted generalised estimating equation Poisson analysis for outpatient infections

CDAI (N=6020)DAS28 (N=3666)
Estimated IRR95% CIp ValueEstimated IRR95% CIp Value
5-Unit change in CDAI
If CDAI <101.141.04 to 1.230.003
If CDAI ≥101.000.96 to 1.04NS
DAS28 (0.6 units)1.041.01 to 1.080.03
Age (10 years)0.910.87 to 0.95<0.0010.910.86 to 0.970.002
Female1.241.09 to 1.400.0011.150.97 to 1.36NS
BMI1.001.00 to 1.01NS1.000.99 to 1.01NS
History of CVD1.251.02 to 1.520.031.381.07 to 1.780.01
History of infections2.842.54 to 3.19<0.0013.152.66 to 3.71<0.001
Disabled1.110.95 to 1.30NS1.090.87 to 1.37NS
HAQ disability index0.920.80 to 1.06NS0.970.80 to 1.17NS
No methotrexate use11
Methotrexate <15 mg/week1.171.02 to 1.340.021.080.89 to 1.31NS
Methotrexate ≥15 mg/week1.130.99 to 1.290.081.110.92 to 1.34NS
TNF inhibitor1.141.02 to 1.270.021.211.04 to 1.410.02
Other DMARD0.970.86 to 1.09NS0.940.79 to 1.12NS
ACR Functional Class I11
ACR Functional Class II1.291.16 to 1.44<0.0011.271.09 to 1.470.002
ACR Functional Class III1.150.95 to 1.40NS1.250.95 to 1.67NS
ACR Functional Class IV1.260.80 to 1.97NS1.550.79 to 3.07NS
  • Additional infection risk at clinical disease activity index (CDAI) ≥10 when compared with low CDAI (<10).

  • Baseline category.

  • ACR, American College of Rheumatology; CVD, cardiovascular disease; DAS28, disease activity score 28; DMARD, disease-modifying antirheumatic drug; HAQ, health assessment questionnaire; IRR, indicent rate ratio; TNF, tumour necrosis factor.