Adjusted generalised estimating equation Poisson analysis for outpatient infections
| CDAI (N=6020) | DAS28 (N=3666) | |||||
|---|---|---|---|---|---|---|
| Estimated IRR | 95% CI | p Value | Estimated IRR | 95% CI | p Value | |
| 5-Unit change in CDAI | ||||||
| If CDAI <10 | 1.14 | 1.04 to 1.23 | 0.003 | – | – | – |
| If CDAI ≥10† | 1.00 | 0.96 to 1.04 | NS | – | – | – |
| DAS28 (0.6 units) | – | – | – | 1.04 | 1.01 to 1.08 | 0.03 |
| Age (10 years) | 0.91 | 0.87 to 0.95 | <0.001 | 0.91 | 0.86 to 0.97 | 0.002 |
| Female | 1.24 | 1.09 to 1.40 | 0.001 | 1.15 | 0.97 to 1.36 | NS |
| BMI | 1.00 | 1.00 to 1.01 | NS | 1.00 | 0.99 to 1.01 | NS |
| History of CVD | 1.25 | 1.02 to 1.52 | 0.03 | 1.38 | 1.07 to 1.78 | 0.01 |
| History of infections | 2.84 | 2.54 to 3.19 | <0.001 | 3.15 | 2.66 to 3.71 | <0.001 |
| Disabled | 1.11 | 0.95 to 1.30 | NS | 1.09 | 0.87 to 1.37 | NS |
| HAQ disability index | 0.92 | 0.80 to 1.06 | NS | 0.97 | 0.80 to 1.17 | NS |
| No methotrexate use‡ | 1 | – | – | 1 | – | – |
| Methotrexate <15 mg/week | 1.17 | 1.02 to 1.34 | 0.02 | 1.08 | 0.89 to 1.31 | NS |
| Methotrexate ≥15 mg/week | 1.13 | 0.99 to 1.29 | 0.08 | 1.11 | 0.92 to 1.34 | NS |
| TNF inhibitor | 1.14 | 1.02 to 1.27 | 0.02 | 1.21 | 1.04 to 1.41 | 0.02 |
| Other DMARD | 0.97 | 0.86 to 1.09 | NS | 0.94 | 0.79 to 1.12 | NS |
| ACR Functional Class I‡ | 1 | – | – | 1 | – | – |
| ACR Functional Class II | 1.29 | 1.16 to 1.44 | <0.001 | 1.27 | 1.09 to 1.47 | 0.002 |
| ACR Functional Class III | 1.15 | 0.95 to 1.40 | NS | 1.25 | 0.95 to 1.67 | NS |
| ACR Functional Class IV | 1.26 | 0.80 to 1.97 | NS | 1.55 | 0.79 to 3.07 | NS |
↵† 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.