Table 1.
Baseline characteristics and environmental factors of all subjects in the Australian and Chinese cohorts
| Australia | China (Hong Kong, Guangzhou, and Kunming) | |||||||
|---|---|---|---|---|---|---|---|---|
| Crohn's disease (n = 100) | Household members (including FDR) (n = 50) | FDR (n = 28) | Healthy controls (n = 20) | Crohn's disease (n = 154) | Household members (including FDR) (n = 72) | FDR (n = 45) | Healthy controls (n = 58) | |
| Age (mean ± SD) | 38.57 ± 14.08 | 45.74 ± 13.51 | 50.86 ± 13.20 | 52.30 ± 13.91 | 37.59 ± 13.57 | 45.34 ± 13.17 | 48.41 ± 13.39 | 43.25 ± 9.21 |
| Weight in kg (mean ± SD) | 72.91 ± 16.63 | 81.00 ± 18.40 | 74.81 ± 12.39 | 78.36 ± 18.35 | 67.10 ± 25.64 | 77.10 ± 32.67 | 80.52 ± 34.56 | 75.74 ± 34.75 |
| Height in cm (mean ± SD) | 170.85 ± 10.65 | 170.51 ± 9.42 | 169.07 ± 6.88 | 170.60 ± 11.49 | 165.22 ± 18.86 | 163.92 ± 7.39 | 163.74 ± 8.09 | 163.43 ± 23.74 |
| Gender (male) n, % | 48, 48.48 | 25, 50.00 | 9, 32.14 | 8, 40.00 | 99, 64.71 | 33, 45.83 | 25, 55.56 | 29, 50.00 |
| Smoking n, % | 39, 39.00 | 19, 38.00 | 6, 21.43 | 8, 40.00 | 37, 24.18 | 18, 25.00 | 14, 31.11 | 17, 29.31 |
| Alcohol n, % | 92, 92.00 | 43, 86.00 | 24, 85.71 | 17, 85.00 | 59, 38.82 | 26, 36.11 | 16, 35.56 | 25, 43.10 |
| Family history of IBD n, % | 34, 34.00 | 15, 30.00 | 23, 85.19 | 2, 10.00 | 8, 5.19 | 53, 73.61 | 38, 84.44 | 0, 0 |
| History of bowel resection beyond 6 months n, % | 35, 35.00 | 1, 2.00 | 1, 3.57 | 0, 0 | 14, 9.09 | 0, 0 | 0, 0 | 0, 0 |
| History of malignancy within 5 years n, % | 3, 3.00 | 5, 10.00 | 2, 7.14 | 1, 5.00 | 1, 0.65 | 0, 0 | 0, 0 | 0, 0 |
| Use of PPI/H2RB/antacids n, % | 11, 11.00 | 3, 6.00 | 3, 10.71 | 3 15.00 | 21, 14.09 | 7, 10.00 | 5, 11.63 | 2, 3.57 |
| Delivered by Caesarean section n, % | 14, 14.14 | 3, 6.12 | 2, 7.14 | 2, 11.10 | 16, 10.96 | 2, 2.86 | 2, 4.76 | 4, 6.90 |
| Breastfed when being a baby n, % | 80, 81.63 | 37, 78.72 | 20, 74.07 | 17, 85.00 | 85, 60.28 | 56, 83.58 | 34, 85.00 | 44, 77.19 |
| Breastfed duration when being a baby (among being breastfed at baby stage), months (mean ± SD) | 8.60 ± 6.63 | 7.85 ± 4.79 | 8.56 ± 5.64 | 6.62 ± 3.40 | 10.89 ± 5.93 | 11.91 ± 6.59 | 10.78 ± 3.91 | 10.32 ± 4.21 |
| Education with University level n, % | 64, 64.00 | 32, 64.00 | 19, 67.86 | 15, 75.00 | 88, 58.28 | 31, 43.06 | 16, 35.56 | 26, 44.83 |
| Living or working near construction area n, % | 16, 16.00 | 5, 10.00 | 3, 10.71 | 5, 25.00 | 64, 42.38 | 31, 43.06 | 21, 46.67 | 33, 56.90 |
| Living or working near mining n, % | 3, 3.00 | 1, 2.00 | 0, 0 | 1, 5.00 | 2, 1.32 | 2, 2.78 | 1, 2.22 | 2, 3.45 |
| Living or working near furnaces n, % | 0, 0 | 1, 2.00 | 0, 0 | 0, 0 | 1, 0.66 | 0, 0 | 0, 0 | 0, 0 |
| Living or working near factories n, % | 4, 4.00 | 3, 6.00 | 2, 7.14 | 1, 5.00 | 21, 13.91 | 9, 12.50 | 2, 4.44 | 3, 5.17 |
| Living or working near busy highways n, % | 26, 26.00 | 18, 36.00 | 9, 32.14 | 5, 25.00 | 33, 21.85 | 10, 13.89 | 4, 8.89 | 10, 17.24 |
| Burn coal as fuel n, % | 0, 0 | 1, 2.00 | 0, 0 | 0, 0 | 7, 4.64 | 3, 4.17 | 3, 6.67 | 3, 5.17 |
| >50% Smog occur in living area in pass 6 months n, % | 12, 12.12 | 7, 14.29 | 1, 3.70 | 4, 20.00 | 12, 8.05 | 7, 9.86 | 3, 6.98 | 6, 10.34 |
| Antibiotics use n, % | ||||||||
| 0–12 months | 23, 23.23 | 10, 20.00 | 8, 28.57 | 3, 15.00 | 30, 20.27 | 8, 11.27 | 3, 6.82 | 15, 25.86 |
| >12 months–5 years | 59, 59.00 | 30, 60.00 | 17, 60.71 | 9, 45.00 | 66, 44.59 | 18, 25.00 | 11, 24.44 | 27, 46.55 |
| >5–10 years | 69, 69.00 | 33, 66.00 | 19, 67.86 | 15, 75.00 | 80, 52.98 | 26, 36.11 | 16, 35.56 | 35, 60.34 |
| >10–18 years | 81, 81.00 | 44, 88.00 | 23, 82.14 | 14, 70.00 | 113, 74.83 | 39, 54.17 | 26, 57.78 | 43, 74.14 |
| Currently | 81, 81.00 | 39, 78.00 | 25, 89.29 | 16, 80.00 | 76, 50.33 | 24, 33.33 | 11, 24.44 | 20, 34.48 |
| Before 18 years | 88, 88.00 | 46, 92.00 | 24, 85.71 | 16, 80.00 | 125, 82.78 | 44, 61.11 | 29, 64.44 | 47, 81.03 |
| Before 10 years | 75, 75.00 | 38, 76.00 | 21, 75.00 | 15, 75.00 | 88, 58.28 | 30, 41.67 | 19, 42.22 | 35, 60.34 |
| Living in city n, % | ||||||||
| 0–12 months | 69, 69.00 | 33, 66.00 | 24, 85.71 | 13, 65.00 | 108, 71.52 | 37, 51.39 | 22, 48.89 | 31, 54.39 |
| >12 months–5 years | 70, 70.00 | 30, 60.00 | 23, 82.14 | 12, 60.00 | 108, 71.52 | 39, 54.17 | 24, 53.33 | 32, 55.17 |
| >5–10 years | 71, 71.00 | 30, 60.00 | 22, 78.57 | 12, 60.00 | 112, 74.17 | 43, 59.72 | 25, 55.56 | 31, 54.39 |
| >10–18 years | 72, 72.00 | 35, 70.00 | 22, 78.57 | 13, 65.00 | 123, 81.46 | 56, 78.87 | 33, 75.00 | 44, 75.86 |
| Currently | 77, 77.00 | 37, 74.00 | 25, 89.29 | 15, 75.00 | 135, 90.00 | 62, 86.11 | 38, 84.44 | 51, 87.93 |
| Before 18 years | 77, 77.00 | 37, 74.00 | 25, 89.29 | 14, 70.00 | 126, 83.44 | 56, 77.78 | 33, 73.33 | 44, 75.86 |
| Before 10 years | 74, 74.00 | 33, 66.00 | 24, 85.71 | 13, 65.00 | 114, 75.50 | 45, 62.50 | 26, 57.78 | 32, 55.17 |
| Running water at home n, % | ||||||||
| 0–12 months | 96, 96.00 | 47, 94.00 | 28, 100 | 20, 100 | 107, 71.33 | 39, 54.17 | 19, 42.22 | 31, 53.45 |
| >12 months–5 years | 98, 98.00 | 48, 96.00 | 28, 100 | 20, 100 | 114, 75.50 | 45, 62.50 | 24, 53.33 | 32, 55.17 |
| >5–10 years | 99, 99.00 | 49, 98.00 | 28, 100 | 20, 100 | 121, 80.13 | 49, 68.06 | 28, 62.22 | 34, 58.62 |
| >10–18 years | 100, 100 | 49, 98.00 | 27, 96.43 | 20, 100 | 130, 86.09 | 63, 87.50 | 38, 84.44 | 44, 75.86 |
| Currently | 100, 100 | 50, 100 | 28, 100 | 20, 100 | 148, 98.01 | 67, 95.71 | 42, 97.67 | 58, 100.00 |
| Before 18 years | 100, 100 | 49, 98.00 | 28, 100 | 20, 100 | 130, 86.09 | 64, 88.89 | 38, 84.44 | 45, 77.59 |
| Before 10 years | 100, 100 | 49, 98.00 | 28, 100 | 20, 100 | 121, 80.13 | 51, 70.83 | 29, 64.44 | 35, 60.34 |
| Hot water from tap n, % | ||||||||
| 0–12 months | 92, 92.00 | 45, 90.00 | 24, 85.71 | 24, 95.00 | 66, 43.71 | 18, 25.00 | 8, 17.78 | 8, 13.79 |
| >12 months–5 years | 93, 93.00 | 46, 92.00 | 24, 85.71 | 24, 95.00 | 70, 46.36 | 19, 26.39 | 9, 20.00 | 9, 15.52 |
| >5–10 years | 93, 93.00 | 47, 94.00 | 24, 85.71 | 24, 95.00 | 78, 51.66 | 22, 30.56 | 11, 24.44 | 10, 17.24 |
| >10–18 years | 97, 97.00 | 48, 96.00 | 25, 89.29 | 20, 100 | 97, 64.24 | 33, 45.83 | 18, 40.00 | 23, 40.35 |
| Currently | 99, 99.00 | 50, 100 | 27, 96.43 | 20, 100 | 120, 79.47 | 59, 81.94 | 38, 84.44 | 41, 70.69 |
| Before 18 years | 97, 97.00 | 48, 96.00 | 25, 89.29 | 20, 100 | 97, 64.24 | 35, 48.61 | 19, 42.22 | 23, 39.66 |
| Before 10 years | 94, 94.00 | 47, 94.00 | 24, 85.71 | 24, 95.00 | 78, 51.66 | 23, 31.94 | 11, 24.44 | 10, 17.24 |
| Flushing toilet at home n, % | ||||||||
| 0–12 months | 93, 93.00 | 44, 88.00 | 23, 82.14 | 16, 80.00 | 64, 42.38 | 17, 23.61 | 9, 20.00 | 17, 29.31 |
| >12 months–5 years | 93, 93.00 | 45, 90.00 | 23, 82.14 | 16, 80.00 | 72, 47.68 | 20, 27.78 | 11, 24.44 | 18, 31.03 |
| >5–10 years | 97, 97.00 | 47, 94.00 | 26, 92.86 | 18, 90.00 | 85, 56.29 | 28, 38.89 | 14, 31.11 | 21, 36.21 |
| >10–18 years | 100, 100 | 49, 98.00 | 26, 92.86 | 20, 100 | 103, 68.21 | 36, 50.00 | 19, 42.22 | 22, 37.93 |
| Currently | 100, 100 | 50, 100 | 28, 100 | 20, 100 | 121, 80.13 | 50, 69.44 | 31, 68.89 | 31, 53.45 |
| Before 18 years | 100, 100 | 49, 98.00 | 27, 96.43 | 20, 100 | 104, 68.87 | 36, 50.00 | 19, 42.22 | 23, 39.66 |
| Before 10 years | 98, 98.00 | 47, 94.00 | 26, 92.86 | 18, 90.00 | 86, 56.95 | 28, 38.89 | 14, 31.11 | 21, 36.21 |
| Keep animal at home n, % | ||||||||
| 0–12 months | 51, 51.00 | 30, 60.00 | 15, 53.57 | 11, 55.00 | 36, 24.16 | 24, 33.33 | 14, 31.11 | 24, 41.38 |
| >12 months–5 years | 61, 61.00 | 34, 68.00 | 20, 71.43 | 14, 70.00 | 50, 33.11 | 29, 40.28 | 18, 40.00 | 31, 53.45 |
| >5–10 years | 72, 72.00 | 37, 74.00 | 23, 82.14 | 14, 70.00 | 55, 36.42 | 36, 50.00 | 22, 48.89 | 32, 56.14 |
| >10–18 years | 82, 82.00 | 41, 82.00 | 24, 85.71 | 17, 85.00 | 53, 35.10 | 28, 38.89 | 19, 42.22 | 27, 46.55 |
| Currently | 70, 70.00 | 41, 82.00 | 20, 71.43 | 15, 75.00 | 27, 18.12 | 13, 18.06 | 9, 20.00 | 14, 24.14 |
| Before 18 years | 86, 86.00 | 45, 90.00 | 25, 89.29 | 18, 90.00 | 80, 52.98 | 43, 59.72 | 27, 60.00 | 43, 74.14 |
| Before 10 years | 76, 84.44 | 39, 88.64 | 24, 88.89 | 14, 87.50 | 68, 48.92 | 40, 57.97 | 24, 57.14 | 38, 71.70 |
| Self‐Smoking n, % | ||||||||
| >5–10 years | 0, 0 | 0, 0 | 0, 0 | 0, 0 | 2, 1.32 | 1, 1.39 | 1, 2.22 | 2, 3.45 |
| >10–18 years | 19, 19.00 | 13, 26.00 | 3, 10.71 | 4, 20.00 | 22, 14.57 | 14, 19.44 | 9, 20.00 | 15, 25.86 |
| Currently | 33, 33.00 | 17, 34.00 | 7, 25.00 | 9, 45.00 | 16, 10.67 | 15, 20.83 | 10, 22.22 | 14, 24.14 |
| Before 18 year | 19, 19.00 | 13, 26.00 | 3, 10.71 | 4, 20.00 | 22, 14.57 | 14, 19.44 | 9, 20.00 | 16, 27.59 |
| Before 10 year | 0, 0 | 0, 0 | 0, 0 | 0, 0 | 2, 1.32 | 1, 1.39 | 1, 2.22 | 2, 3.45 |
| Family smoking n, % | ||||||||
| 0–12 months | 47, 47.00 | 28, 56.00 | 20, 71.43 | 8, 45.00 | 69, 46.31 | 39, 54.17 | 24, 53.33 | 36, 62.07 |
| >12 months–5 years | 49, 49.00 | 29, 58.00 | 20, 71.43 | 10, 50.00 | 71, 47.02 | 39, 54.93 | 24, 54.55 | 37, 63.79 |
| >5–10 years | 45, 45.00 | 28, 56.00 | 18, 64.29 | 8, 40.00 | 73, 48.67 | 40, 55.56 | 26, 57.78 | 34, 59.65 |
| >10–18 years | 41, 41.00 | 23, 46.00 | 16, 57.14 | 7, 35.00 | 72, 47.68 | 39, 54.17 | 24, 53.33 | 34, 58.62 |
| Currently | 35, 35.00 | 14, 28.00 | 14, 50.00 | 4, 20.00 | 44, 29.14 | 17, 23.61 | 8, 17.78 | 22, 37.93 |
| Before 18 years | 52, 52.00 | 32, 64.00 | 20, 71.43 | 12, 60.00 | 83, 54.97 | 46, 63.89 | 28, 62.22 | 41, 70.69 |
| Before 10 years | 50, 50.00 | 31, 62.00 | 20, 71.43 | 11, 55.00 | 76, 50.33 | 42, 58.33 | 27, 60.00 | 38, 65.52 |
| Migration n, % | ||||||||
| 0–12 months | 20, 20.00 | 15, 30.00 | 6, 21.43 | 6, 30.00 | 14, 9.33 | 2, 2.78 | 1, 2.22 | 4, 6.90 |
| >12 months–5 years | 22, 22.00 | 15, 30.61 | 6, 22.22 | 4, 20.00 | 14, 9.27 | 2, 2.78 | 1, 2.22 | 5, 8.62 |
| >5–10 years | 19, 19.00 | 12, 24.00 | 5, 17.86 | 5, 25.00 | 5, 3.31 | 3, 4.17 | 2, 4.44 | 4, 6.90 |
| >10–18 years | 20, 20.00 | 10, 20.00 | 7, 25.00 | 4, 20.00 | 11, 7.28 | 4, 5.56 | 2, 4.44 | 3, 5.17 |
| Currently | 25, 25.00 | 14, 28.00 | 9, 32.14 | 7, 35.00 | 12, 7.95 | 3, 4.17 | 3, 6.67 | 3, 5.17 |
| Before 18 years | 28, 28.00 | 17, 34.00 | 8, 28.57 | 7, 35.00 | 24, 15.89 | 5, 6.94 | 3, 6.67 | 9, 15.52 |
| Before 10 years | 23, 23.00 | 16, 32.00 | 6, 21.43 | 7, 35.00 | 15, 9.93 | 3, 4.17 | 2, 4.44 | 6, 10.34 |
FDR, first‐degree relatives; IBD, inflammatory bowel disease.