Table 3.
Age-group stratified familial risk of incident UC and CD with affected FDR of the same subtype according to type of family relationship
| Age group (years) | With affected father* | With affected mother* | With affected sibling* | With affected twin* | With more than oneaffected FDR* | With positive family history* | No family history of IBD) | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
|
| |||||||||||||||
| N (%) | IRRs (95% CI) | N (%) | IRRs (95% CI) | N (%) | IRRs (95% CI) | N (%) | IRRs (95% CI) | N (%) | IRRs (95% CI) | Person-years | N (%) | IRRs (95% CI) | Person-years | N (%) | |
|
| |||||||||||||||
| CD | |||||||||||||||
| 0 to <10 | 0 | - | 1(5) | 15.93(0.4–89.53) | 5(1) | 47.37(15.2–111.9) | 0 | - | 0 | - | 83,891 | 6(1) | 19.63 (7.14–43.32) | 70,542,448 | 257(2) |
| 10 to <20 | 29(78) | 15.12(10.1–21.7) | 10(50) | 8.27(3.96–15.23) | 165(54) | 34.06(29–39.77) | 18(60) | 379.4(224.69–600.17) | 6(60) | 138.23(50.71–301.05) | 125,009 | 228(57) | 28.28(24.67–32.29) | 87,510,480 | 5643(19) |
| 20 to <30 | 7(19) | 5.09(2.05–10.50) | 6(35) | 5.36(1.97–11.67) | 113(38) | 24.04(19.7–28.9) | 12(40) | 352.4(181.97–616.11) | 3(30) | 80.14(16.52–234.33) | 116,182 | 141(36) | 19.41(16.30–22.94) | 80,635,807 | 5043(42) |
| 30 to <40 | 1(3) | 2.32(0.06–12.93) | 2(10) | 4.91(0.59–17.77) | 19(6) | 15.34(9.2–24.0) | 0 | - | 3(10) | 102.41(2.59–571.37) | 61,269 | 23(6) | 10.99(6.94–16.54) | 48,287,779 | 1650(26) |
| 40 to <50 | 0 | - | 0 | - | 2(1) | 14.88(1.7–54.1) | 0 | - | 0 | - | 14,274 | 2(0) | 6.83(0.82–24.88) | 15,605,220 | 320(8) |
| 50 + | 0 | - | 0 | - | 0 | - | 0 | - | 0 | - | 2,429 | 0 | - | 4,422,586 | 70(3) |
| Total | 37 | 9.40(6.81–12.98) | 19 | 6.54(4.17–10.25) | 304 | 27.56(24.5–30.8) | 30 | 336.21(234.96–481.08) | 10 | 107.52(57.84–199.89) | 403,054 | 400 | 22.15(20.05–24.47) | 307,000,000 | 12983 |
| UC | |||||||||||||||
| 0 to <10 | 1(1) | 2.60(0.07–14.60) | 3(2) | 11.42(2.3–33.7) | 5(2) | 74.84(24.1–176.8) | 0 | - | 0 | - | 190,012 | 9(2) | 12.51(5.6–24.1) | 70,542,448 | 267(2) |
| 10 to<20 | 46(28) | 10.75(7.8–14.3) | 39(27) | 13.66(9.6–18.7) | 60(29) | 30.33(23.08–39.15) | 6(30) | 284.63(104.36–620.2) | 8(21) | 120.35(51.9–237.4) | 280,616 | 159(28) | 17.23(14.6–20.2) | 87,510,480 | 2877(19) |
| 20 to <30 | 71(43) | 7.07(5.51–8.93) | 67(46) | 9.67(7.48–12.92) | 84(42) | 11.73(9.34–14.54) | 11(55) | 182.45(91.03–326.68) | 25(66) | 104.23(67.4–154) | 315,036 | 258(45) | 10.54(9.2–11.9) | 80,635,807 | 6268(42) |
| 30 to <40 | 35(21) | 5.51(3.83–7.67) | 27(18) | 5.77(3.8–8.41) | 45(21) | 8.84(6.44–11.85) | 2(10) | 67.02(8.11–242.28) | 5(13) | 29.68(9.63–69.33) | 202,375 | 114(20) | 6.97(5.7–8.4) | 48,287,779 | 3902(26) |
| 40 to <50 | 11(6) | 6.37(3.17–11.43) | 11(7) | 7.19(3.58–12.92) | 11(5) | 9.18(4.57–16.49) | 1(5) | 114.76(2.9–640.55) | 0 | - | 56,474 | 34(6) | 7.54(5.2–10.5) | 15,605,220 | 1246(8) |
| 50 + | 1(1) | 2.38(0.06–13.33) | 0 | - | 1(1) | 4.09(0.1–22.91) | 0 | - | 0 | - | 12,173 | 2(1) | 1.70(0.2–6.1) | 4,422,586 | 428(3) |
| Total | 165 | 7.11(6.10–8.29) | 147 | 8.77(7.46–10.32) | 206 | 13.09(11.41–15.02) | 20 | 163.73(105.60–253.86) | 38 | 72.36(52.63–99.49) | 1,056,686 | 576 | 10.2(9.3–11.0) | 307,000,000 | 14,988 |
*
Familial risk of incident IBD with same subtype of affected FDR (e.g. risk of UC with UC affected FDR)
N – number of individuals, IBD – inflammatory bowel disease, UC - ulcerative colitis, CD - Crohn’s disease, FDR – first degree relatives, IRR – incidence risk ratio,