Table 1.
Demographic and substance use characteristics of African-American and European American female twin and sibling pairs.
| African-American n=956 | European-American n=3557 | |
|---|---|---|
| MOFAM participant % (n) | 42.3% (N=405) | 9.2% (N=326) |
| MOAFTS participant % (n) | 57.6% (N=551) | 90.8% (N=3231) |
| Study Design Group | ||
| MOFAM low risk | 17.6% (N=168) | 2.8% (N=98) |
| MOFAM high risk | 12.8% (N=122) | 2.0% (N=70) |
| MOFAM very high risk | 12.0% (N=115) | 4.4% (N=158) |
| MOAFTS (general population) | 57.6% (N=551) | 90.8% (N=3231) |
| MOAFTS: Monozygotic twin (MZ), % (n) | 24.6% (N=235, with 111 pairs) | 50.3% (N=1790, with 853 pairs) |
| MOAFTS: Dizygotic twin (DZ), % (n) | 33.1% (N=316, with 143 pairs) | 40.5 (N=1441, with 663 pairs) |
| MOFAM: Full Sibling (FS), % (n) | 42.4 (N=405, with 88 pairs and 13 trios) | 9.2 (N=326, with 75 pairs and 17 trios) |
| Mean age at first interview (SD) | 18.0 (3.8) | 16.8 (3.3) |
| MOFAM | 17.8 (3.7) | 17.3 (3.4) |
| MOAFTS | 18.2 (3.9) | 16.7 (3.3) |
| Mean age at last interview (SD) | 23.5 (3.9) | 24.2 (3.0) |
| MOFAM | 21.6 (4.3) | 21.5 (4.1) |
| MOAFTS | 24.8 (2.8) | 24.5 (2.7) |
| Ever smoked a cigarette*, % | 64.2% (61.2 – 67.2) | 75.3% (73.8 – 76.7) |
| MOFAM | 59.5% (54.7 – 64.3) | 66.6% (61.4 – 71.7) |
| MOAFTS | 67.6% (63.7 – 71.6) | 76.1% (74.7 – 77.6) |
| Mean age at cigarette use (SD) | 14.6 (3.5) | 14.1 (3.2) |
| MOFAM | 14.9 (3.4) | 14.2 (3.4) |
| MOAFTS | 14.4 (3.6) | 14.1 (3.2) |
| Ever tried cannabis*, % | 55.5% (52.5 – 58.8) | 52.4% (50.7 – 54.0) |
| MOFAM | 52.8% (48.0 – 57.7) | 50.6% (45.2 – 56.0) |
| MOAFTS | 57.7% (53.6 – 61.8) | 52.5% (50.8 – 54.2) |
| Mean age at cannabis use (SD) | 16.6 (2.7) | 16.7 (2.5) |
| MOFAM | 16.0 (2.4) | 16.0 (2.5) |
| MOAFTS | 17.1 (2.7) | 16.8 (2.5) |
| Substance Use Profile | ||
| Neither substance* | 26.5% (23.7 – 29.3) (N=253) | 22.7% (21.3 – 24.0) (N=806) |
| Cigarettes only* | 17.8% (15.4 – 20.2) (N=170) | 25.0% (23.6 – 26.4) (N=889) |
| Cannabis only* | 9.3% (7.5 – 11.2) (N=89) | 2.1% (1.6 – 2.6) (N=74) |
| Both cigarettes and cannabis* | 46.4% (43.2 – 49.6) (N=443) | 50.3% (48.6 – 51.9) (N=1788) |
| Substance use sequence | ||
| Cigarettes first* | 61.3% (56.7 – 65.8) (N=269) | 80.3% (78.4 – 82.2) (N=1418) |
| Both within same year | 15.3% (11.9 – 18.6) (N=67) | 14.3% (12.6 – 15.9) (N=252) |
| Cannabis first* | 23.5% (19.5 – 27.4) (N=103) | 5.4% (4.4 – 6.5) (N=96) |
*
Significantly different between EA and AA women