Table 2.
Crude rates of serious infections per 100 patient-years (pyrs)
| Serious infections | |||||
|---|---|---|---|---|---|
| Exposure time (pyrs) | n | Per 100 pyrs | 95% CI | Incidence rate ratio (IRR) | |
| Year 1 | |||||
| DMARD treatment | 1765 | 40 | 2.3 | 1.6 to 3.1 | 2.13 |
| Anti-TNF agents | 3041 | 147 | 4.8 | 4.1 to 5.7 | |
| Year 2 | |||||
| DMARD treatment | 1696 | 40 | 2.4 | 1.7 to 3.2 | 1.36 |
| Anti-TNF agents | 2564 | 82 | 3.2 | 2.9 to 4.0 | |
| Year 3 | |||||
| DMARD treatment | 1397 | 35 | 2.5 | 1.8 to 3.5 | 0.88 |
| Anti-TNF agents | 2186 | 48 | 2.2 | 1.6 to 2.9 | |
DMARD, disease-modifying antirheumatic drug; TNF, tumour necrosis factor.