Table 1.
Description of Study Sample: Patients, Siblings, and Controls
| Variable | Patients (N = 215) | Siblings (N = 187) | Controls (N = 98) | χ2 or F | P |
|---|---|---|---|---|---|
| Gender: Male, % | 84.2 | 42.8 | 62.2 | 75.0 | <.001 |
| Age, mean (SD) | 26.3 (7.6) | 27.6 (8.5) | 27.6 (10.4) | 1.4 | .256 |
| Ethnicitya (%) | |||||
| European | 63.7 | 74.3 | 77.6 | 14.0 | .30 |
| North-African | 4.2 | 3.2 | 5.1 | ||
| Surinamese | 4.2 | 3.7 | 3.1 | ||
| Turkish | 3.3 | 3.7 | 0 | ||
| Dutch Caribbean | 0.9 | 0 | 0 | ||
| Mixed | 14.4 | 11.2 | 6.1 | ||
| Other | 2.8 | 1.6 | 3.1 | ||
| IQb mean (SD) | 94.1 (16.2) | 102.9 (14.6) | 105.8 (16.3) | 23.9 | <.001 |
| BMIc mean (SD) | 24.2 (4.6) | 23.0 (3.4) | 22.5 (2.8) | 8.2 | <.001 |
| Cannabisd | |||||
| Urine positive % | 17.7 | 7.0 | 8.2 | 11.7 | .003 |
| Tobaccoe | |||||
| Daily/12 mo.% | 66.0 | 33.7 | 26.5 | 63.4 | <.001 |
aMissings patients, siblings, controls (%): 6.5; 2.1; 5.0
bIQ = Intelligence Quotient
Missings patients, siblings, controls (%): 7.0; 9.0; 4.0
cBMI = Body Mass Index
Missings patients, siblings, controls (%): 9.3; 10.0; 4.1
dMissings patients, siblings, controls (%): 7.4; 9.6; 13.3
eMissings patients, siblings, controls (%): 3.7; 3.2; 4.1