Table 1.
Descriptive statistics for sibling pairs born in Sweden 1960-1990. Individuals may belong to more than one sibling pair.
| Women | Monozygotic twins | Dizygotic twins | Full siblings | Half siblings reared together | Half siblings reared apart | ||||||||||
| N Pairs | 3,186 | 2,570 | 275,668 | 9,828 | 19,166 | ||||||||||
| % Suicide attempt | 3.2% | 3.5% | 3.7% | 6.5% | 7.1% | ||||||||||
| % Suicide death | 0.2% | 0.2% | 0.2% | 0.4% | 0.4% | ||||||||||
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| Median (Q1, Q3) age at suicidal event | Median | Q1 | Q3 | Median | Q1 | Q3 | Median | Q1 | Q3 | Median | Q1 | Q3 | Median | Q1 | Q3 |
| Suicide attempt | 24 | 19 | 32 | 26 | 20 | 35 | 23 | 18 | 31 | 22 | 17 | 30 | 22 | 17 | 32 |
| Suicide death | 39 | 35 | 42 | 26.5 | 20 | 33.5 | 30 | 23 | 39 | 27 | 23 | 34.5 | 28 | 23 | 38 |
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| Tetrachoric correlations (95% CI) | |||||||||||||||
| SA between siblings | 0.57 | 0.49; 0.65 | 0.25 | 0.13; 0.27 | 0.28 | 0.27; 0.29 | 0.17 | 0.12; 0.21 | 0.12 | 0.09; 0.15 | |||||
| SD between siblings | n/a | n/a | n/a | n/a | 0.25 | 0.18; 0.32 | n/a | n/a | 0.17 | −0.03; 0.37 | |||||
| Within sibling SA and SD | 0.50 | 0.28; 0.73 | 0.47 | 0.21; 0.73 | 0.52 | 0.50; 0.54 | 0.45 | 0.36; 0.54 | 0.43 | 0.37; 0.50 | |||||
| Between sibling SA and SD | 0.33 | 0.04; 0.61 | 0.21 | −0.15; 0.57 | 0.16 | 0.12; 0.19 | 0.15 | 0.02; 0.27 | 0.01 | −0.09; 0.11 | |||||
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| Men | Monozygotic twins | Dizygotic twins | Full siblings | Half siblings reared together | Half siblings reared apart | ||||||||||
| N Pairs | 2,646 | 2,294 | 310,569 | 10,138 | 21,430 | ||||||||||
| % Suicide attempt | 3.2% | 3.0% | 3.4% | 6.5% | 6.3% | ||||||||||
| % Suicide death | 0.3% | 0.4% | 0.5% | 0.9% | 0.9% | ||||||||||
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| Median (Q1, Q3) age at suicidal event | Median | Q1 | Q3 | Median | Q1 | Q3 | Median | Q1 | Q3 | Median | Q1 | Q3 | Median | Q1 | Q3 |
| Suicide attempt | 28 | 22 | 35 | 28.5 | 23 | 35 | 26 | 20 | 34 | 26 | 20 | 33 | 26 | 20 | 35 |
| Suicide death | 31 | 26 | 36 | 29.5 | 26 | 39 | 29 | 23 | 37 | 29 | 24 | 38 | 29 | 23 | 37 |
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| Tetrachoric correlations (95% CI) | |||||||||||||||
| SA between siblings | 0.41 | 0.30; 0.52 | 0.29 | 0.16; 0.43 | 0.30 | 0.29; 0.31 | 0.19 | 0.15; 0.24 | 0.12 | 0.09; 0.16 | |||||
| SD between siblings | 0.83 | 0.69; 0.96 | n/a | n/a | 0.20 | 0.17; 0.24 | 0.14 | −0.02; 0.30 | 0.12 | 0.01; 0.23 | |||||
| Within sibling SA and SD | 0.45 | 0.25; 0.66 | 0.60 | 0.43; 0.76 | 0.44 | 0.42; 0.45 | 0.36 | 0.29; 0.43 | 0.38 | 0.33; 0.43 | |||||
| Between sibling SA and SD | 0.23 | −0.04; 0.50 | 0.23 | −0.04; 0.51 | 0.15 | 0.13; 0.18 | 0.13 | 0.04; 0.22 | 0.09 | 0.02; 0.15 | |||||
SA=suicide attempt; SD=suicide death; CI=confidence intervals; n/a=cannot be estimated due to sample size).