Table 1 The effect of unique family-related variables on the odds of developing schizophrenia: results from the multivariate conditional logistic regression model which used the matched case-sibling design, odds ratios with 95% confidence intervals.
From: Family structure and risk factors for schizophrenia: case-sibling study
Sex (female vs. male) | 0.507(0.478, 0.537) |
Siblings who were less than 5 years older (yes vs. no) | 1.463(1.288, 1.661) |
Siblings who were 5–10 years older (yes vs. no) | 0.905(0.800, 1.025) |
Over 10 years older siblings (yes vs. no) | 0.661(0.556, 0.785) |
Birth order | |
1 | (reference) |
2 | 0.618(0.535, 0.715) |
3 | 0.542(0.441, 0.666) |
4+ | 0.504(0.382, 0.667) |
Birth cohort | |
1950–1955 | (reference) |
1956–1960 | 1.143(1.032, 1.267) |
1961–1965 | 1.199(1.015, 1.415) |
1966–1976 | 0.956(0.746, 1.224) |
Maternal age | |
under 20 | (reference) |
20–25 | 0.794(0.671, 0.939) |
26–30 | 0.688(0.555, 0.852) |
31–35 | 0.614(0.470, 0.803) |
over 35 | 0.605(0.433, 0.845) |
Paternal age | |
under 20 | (reference) |
20–25 | 1.382(0.990, 1.927) |
26–30 | 1.432(1.004, 2.043) |
31–35 | 1.340(0.915, 1.963) |
over 35 | 1.332(0.880, 2.015) |
not available | 0.213(0.018, 2.491) |