Table 2. Baseline Characteristics of the Family and Case–Control Samples.
| Variable |
African-American |
European-American |
||
|---|---|---|---|---|
| Family (N=2116) | CC (N=1912) | Family (N=1705) | CC (N=1476) | |
| Mean age (SD) | 40.7 (7.5) | 40.7 (9.9) | 38.0 (11.2) | 38.2 (10.8) |
| Male (%) | 52 | 54 | 53 | 57 |
| OD/control (N) | 311/721 | 349/1519 | 480/306 | 624/807 |
| CD/control (N) | 874/147 | 1273/587 | 595/176 | 790/615 |
| ND/control (N) | 644/401 | 1014/879 | 584/229 | 834/622 |
| AD/control (N) | 462/375 | 1061/611 | 394/217 | 740/463 |
| Two SD diagnoses (N) | 355 | 439 | 194 | 310 |
| Three SD diagnoses (N) | 311 | 431 | 267 | 275 |
| Four SD diagnoses (N) | 110 | 117 | 167 | 69 |
Abbreviations: AD, alcohol dependence; CC, case control; CD, cocaine dependence; ND, nicotine dependence; OD, opioid dependence; SD, substance dependence
Overall numbers reflect the number of family members recruited to the study; case and control numbers reflect the number of participants with non-missing genotype and phenotype data.