Table 1.
Odds ratios (ORs) with 95% confidence intervals (CIs) describing the risk of hospital diagnosis of schizophrenia after prior registration for cannabis abuse (CA) in (i) a general population sample and (ii) a co-relative sample, allowing the time between exposure and disease to vary by 1, 3, 5 and 7 years
| At baseline | After 1 year | After 3 years | After 5 years | After 7 years | |
|---|---|---|---|---|---|
| (i) General population sample | 10.44 (8.99–12.11) | 9.19 (7.89–10.70) | 7.69 (6.57–9.00) | 5.95 (5.04–7.02) | 4.24 (3.54–5.07) |
| (n = 5456) | (n = 5388) | (n = 5306) | (n = 5210) | (n = 5119) | |
| (ii) Co-relative sample | |||||
| First-cousin pairs | 9.40 (8.12–10.87) | 8.37 (7.22–9.70) | 7.19 (6.19–8.35) | 5.85 (5.03–6.81) | 4.05 (3.46–4.73) |
| (n = 2079) | (n = 1836) | (n = 1605) | (n = 1343) | (n = 989) | |
| Paternal half-sibling pairs | 9.15 (6.39–13.11) | 8.42 (5.87–12.09) | 7.82 (5.44–11.23) | 6.12 (4.24–8.84) | 4.18 (2.86–6.11) |
| (n = 342) | (n = 328) | (n = 298) | (n = 239) | (n = 173) | |
| Maternal half-siblings pairs | 6.00 (4.20–8.58) | 5.85 (4.04–8.46) | 4.70 (3.23–6.84) | 3.42 (2.32–5.05) | 2.58 (1.72–3.85) |
| (n = 245) | (n = 226) | (n = 188) | (n = 146) | (n = 118) | |
| Full-sibling pairs | 5.07 (4.17–6.16) | 4.47 (3.66–5.47) | 3.71 (3.02–4.55) | 2.80 (2.27–3.46) | 1.98 (1.59–2.48) |
| (n = 728) | (n = 635) | (n = 546) | (n = 441) | (n = 346) | |
| MZ twins (extrapolated) | 3.92 | 3.38 | 3.31 | 2.63 | 1.67 |
MZ, Monozygotic.