Table 1.
The Prevalence of Drinking to Celebrate the 21st Birthday and the Number of Drinks Consumed Among Birthday Drinkers by Risk Factor, With Univariate and Multivariate Analyses
| Drinking to celebrate the 21st birthday |
Number of drinks for birthday drinkers |
|||||
|---|---|---|---|---|---|---|
| Risk factor | Percent drinking | Univariate OR (95% CI)a | Multivariate OR (95% CI)b | M drinks (SD; Q1–Q3) | Univariate analyses rc | Multivariate analysis β (b)d |
| Gender | ||||||
| Female (1; n = 1,510) | 85 | 1.4 (1.2, 1.8) | 1.7 (1.3, 2.2) | 11.4 (7.8; 5−19) | −.18*** | −.15*** (−2.76) |
| Male (0; n = 1,008) | 80 | 14.6 (9.0; 7−21) | ||||
| Race/ethnicity | ||||||
| White, non-Hispanic (1; n = 2,280) | 84 | 2.4 (1.8, 3.2) | 2.0 (1.4, 3.1) | 12.8 (8.5; 5−21) | .10*** | .03 (0.80) |
| Other (0; n = 237) | 69 | 9.8 (8.1; 3−15) | ||||
| College student status | ||||||
| College student (1; n = 2,387) | 83 | 1.3 (0.8, 2.0) | 1.5 (0.8, 3.0) | 12.6 (8.4; 5−21) | −.01 | −.01 (−0.65) |
| Nonstudent (0; n = 121) | 79 | 13.0 (9.0; 5−21) | ||||
| Greek status | ||||||
| Member (1; n = 707) | 90 | 2.4 (1.8, 3.1) | 1.5 (1.1, 2.2) | 16.9 (7.9;10−22) | .34*** | .27*** (4.89) |
| Nonmember (0; n = 1,770) | 80 | 10.6 (8.0; 4−15) | ||||
| Drunkenness | ||||||
| At least once (1; n = 1,641) | 90 | 6.4 (5.0, 8.1) | 4.2 (3.1, 5.8) | 13.6 (8.1; 6−21) | .36*** | .22*** (5.12) |
| Never (0; n = 445) | 57 | 5.1 (5.2; 1−7) | ||||
| Alcohol dependence (3+ symptoms) | ||||||
| At 1+ waves (1; n = 560 ) | 94 | 4.1 (2.9, 6.0) | 1.8 (1.1, 2.8) | 16.7 (8.1;10−22) | .36*** | .21*** (3.88) |
| At no waves (0; n = 1,531) | 78 | 10.3 (7.6; 4−16) | ||||
| Cigarette use in past 30 days | ||||||
| 3+ days (1; n = 370) | 93 | 3.2 (2.1, 4.8) | 1.3 (0.8, 2.2) | 15.3 (8.2; 9−21) | .18*** | .01 (0.14) |
| 2 or fewer days (0; n = 1,668) | 80 | 11.6 (8.3; 5−20) | ||||
| Illegal/illicit drug use | ||||||
| Any use (1; n = 677) | 90 | 2.4 (1.8, 3.2) | 0.9 (0.6, 1.4) | 14.7 (8.3; 8−21) | .23*** | .02 (0.34) |
| No use (0; n = 1,318) | 79 | 10.8 (7.9; 4−18) | ||||
| First full drink at age 14 or younger | ||||||
| At 14 or younger (1; n = 857) | 89 | 2.1 (1.7, 2.7) | 1.2 (0.8, 1.7) | 15.0 (8.3; 8−21) | .21*** | .06* (1.08) |
| After 14 or never (0; n = 1,656) | 79 | 11.2 (8.3; 4−18) | ||||
| First time drunk at age 16 or younger | ||||||
| At 16 or younger (1; n = 1,190) | 92 | 3.8 (3.0, 4.8) | 1.6 (1.1, 2.3) | 15.0 (8.3; 8−21) | .30*** | .07** (1.22) |
| After 16 or never (0; n = 1,319) | 75 | 9.9 (7.8; 3−15) | ||||
| Conduct problem before age 15 | ||||||
| Any problem (1; n = 619) | 84 | 1.2 (0.9, 1.5) | 0.9 (0.7, 1.3) | 13.9 (8.6; 6−21) | .12*** | .004 (0.07) |
| No problem (0; n = 1,540) |
82 |
|
|
11.7 (8.3; 5−20) |
|
|
| Variance accounted for | c = .76 | Adjusted R2 = .31 | ||||
Note. Due to missing data, sample sizes differ across analyses. OR = odds ratio; CI = confidence interval; Q1 = 1st quartile; Q3 = 3rd quartile; β = standardized estimate; b = unstandardized estimate.
a
ns = 1,995−2,518.
b
n = 1,692.
c
ns = 1,644−2,084.
d
n = 1,383.
*
p < .05.
**
p < .01.
***
p < .001.