Incidence of serious infection
| RA | PsA | |
| Treatment courses TNFi, n | 1778 | 1391 |
| Person-years | 3139 | 2590 |
| Serious infection, n | 131 | 56 |
| Crude IR/100 PY (95% CI) | 4.17 (3.52 to 4.95) | 2.16 (1.66 to 2.81) |
| Incidence rate ratio (95% CI) | 0.52 (0.37 to 0.71) | |
IR, incidence rate; PsA, psoriatic arthritis; PY, person years; RA, rheumatoid arthritis; TNFi, tumour necrosis factor inhibitor.