Number of patients with JIA and general population individuals, number of incident cancer cases, person-years, standardised incidence rates and Cox HR with 95% CI.
| Individuals (n) | Cancers (n) | Person-years | Incidence (/1000 person-years) | HR | 95% CI | |
| A. Follow-up until age 18 | ||||||
| All cancer | ||||||
| JIA | 6721 | 10 | 34 951 | 0.29 | 1.43 | 0.71 to 2.88 |
| General population | 33 774 | 35 | 174 529 | 0.20 | ||
| Lymphoproliferative malignancies | ||||||
| JIA | 6721 | 5 | 34 951 | 0.14 | 3.57 | 1.13 to 11.24 |
| General population | 33 774 | 7 | 174 529 | 0.04 | ||
| B. Follow-up through all ages | ||||||
| All cancer | ||||||
| JIA | 6721 | 18 | 55 107 | 0.33 | 1.10 | 0.66 to 1.84 |
| General population | 33 814 | 82 | 276 383 | 0.30 | ||
| Lymphoproliferative malignancies | ||||||
| JIA | 6721 | 7 | 55 107 | 0.13 | 3.19 | 1.24 to 8.24 |
| General population | 33 814 | 11 | 276 383 | 0.04 | ||
JIA, juvenile idiopathic arthritis.