Table 2.
SIRs for inflammatory diseases in siblings by age at diagnosis—Males and females, Sweden, 1973–2004
| AS |
SLE |
RA |
|||||||
|---|---|---|---|---|---|---|---|---|---|
| Age at diagnosis (yrs) | O | SIR | 95% CI | O | SIR | 95% CI | O | SIR | 95% CI |
| Males | |||||||||
| <30 | 20 | 5.01 | 2.16, 10.95 | 7 | 12.29 | 3.44, 36.00 | 19 | 5.36 | 2.28, 11.86 |
| 30–39 | 38 | 4.40 | 2.20, 8.55 | 1 | 1.69 | 0.00, 13.70 | 33 | 5.58 | 2.71, 11.09 |
| 40–49 | 24 | 3.09 | 1.40, 6.51 | 6 | 6.20 | 1.58, 19.20 | 62 | 5.57 | 3.02, 10.10 |
| 50–59 | 13 | 4.22 | 1.58, 10.23 | 0 | 50 | 3.95 | 2.07, 7.36 | ||
| ≥60 | 4 | 9.02 | 1.66, 33.00 | 1 | 2.43 | 0.00, 19.71 | 15 | 3.22 | 1.27, 7.54 |
| All | 99 | 4.14 | 2.38, 7.13 | 15 | 4.35 | 1.71, 10.16 | 179 | 4.72 | 2.87, 7.73 |
| Females | |||||||||
| <30 | 7 | 4.48 | 1.25, 13.11 | 13 | 3.77 | 1.41, 9.13 | 52 | 5.93 | 3.13, 11.00 |
| 30–39 | 19 | 5.32 | 2.26, 11.76 | 26 | 5.16 | 2.38, 10.70 | 96 | 5.74 | 3.29, 9.92 |
| 40–49 | 14 | 4.64 | 1.79, 11.05 | 16 | 3.03 | 1.22, 6.98 | 131 | 4.15 | 2.45, 6.96 |
| 50–59 | 6 | 4.32 | 1.10, 13.37 | 9 | 2.55 | 0.82, 6.88 | 100 | 3.20 | 1.84, 5.51 |
| ≤60 | 0 | 4 | 4.20 | 0.77, 15.36 | 28 | 2.70 | 1.27, 5.53 | ||
| All | 46 | 4.73 | 2.45, 8.93 | 68 | 3.73 | 2.05, 6.68 | 407 | 4.12 | 2.64, 6.43 |
Bold type: 95% CI does not include 1.00. O: observed number of sibling cases.