Table 1.
Distribution of each violation of the gateway pattern of drug use initiation by age cohort. Data from the National Comorbidity Survey Replication (NCS-R), 2001–2003
| 18–29 yr (n=1371) |
30–44 yr (n=1826) |
45–59 yr (n=1521) |
⩾ 60 yr (n=974) |
Total (n=5692) |
||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Order of onset of use | % | S.E. | n | % | S.E. | n | % | S.E. | n | % | S.E. | n | % | S.E. | n | Significance |
| 01. Cannabis before alcohol, not tobacco | 4.7 | 1.0 | 51 | 3.6 | 0.5 | 87 | 1.1 | 0.3 | 24 | –a | – | 1 | 2.5 | 0.2 | 163 | 88.2* |
| 02. Cannabis before tobacco, not alcohol | 9.5 | 1.1 | 144 | 10.2 | 1.0 | 222 | 6.8 | 0.9 | 102 | –a | – | 3 | 7.0 | 0.4 | 471 | 138.2* |
| 03. Cannabis before alcohol and tobacco | 2.0 | 0.7 | 23 | 3.0 | 0.8 | 50 | 1.1 | 0.2 | 20 | –a | – | 1 | 1.6 | 0.3 | 94 | 45.7* |
| 04. Other illicit drugs before alcohol, not tobacco | 0.2 | 0.1 | 5 | 0.7 | 0.2 | 16 | 0.3 | 0.1 | 7 | 0.5 | 0.3 | 3 | 0.4 | 0.1 | 31 | 5.6 |
| 05. Other illicit drugs before tobacco, not alcohol | 2.0 | 0.4 | 35 | 3.7 | 0.5 | 86 | 2.6 | 0.7 | 40 | –a | – | 0 | 2.2 | 0.3 | 161 | 75.9* |
| 06. Other illicit drugs before alcohol and tobacco | 1.2 | 0.3 | 18 | 1.1 | 0.3 | 25 | 0.9 | 0.3 | 14 | –a | – | 0 | 0.8 | 0.1 | 57 | 50.9* |
| 07. Other illicit drugs before cannabis | 3.9 | 0.6 | 64 | 4.6 | 0.6 | 91 | 4.4 | 0.6 | 81 | 1.3 | 0.5 | 16 | 3.7 | 0.2 | 252 | 22.9* |
| Any violation of the gateway order of initiation (03, 06, 07) | 5.9 | 0.9 | 87 | 7.4 | 1.0 | 137 | 5.4 | 0.7 | 100 | 1.3 | 0.5 | 17 | 5.2 | 0.3 | 341 | 35.3* |
| Any of 01 to 07 | 19.6 | 1.5 | 274 | 21.0 | 1.6 | 437 | 13.3 | 1.2 | 223 | 1.6 | 0.5 | 21 | 14.5 | 0.6 | 955 | 130.9* |
S.E., Standard error.
a
A statistically reliable estimate could not be made.
*
Significant at 0.01 level, two-tailed test.