Table 2. Characteristics associated with being a designated driver, 2007.
| Variable | Crude Prevalence Ratio |
95% Confidence Interval |
Adjusted Prevalence Ratio |
95 % Confidence Interval |
|---|---|---|---|---|
| Gender | ||||
| Female | 1.1 | (1.0,1.1) | 1.1 | (1.0, 1.1) |
| Reference: Male | ||||
| Age Group | ||||
| Under 21 years | 1.4 | (1.3,1.5) | 1.3 | (1.2, 1.5) |
| 21-34 years | 1.5 | (1.4, 1.6) | 1.4 | (1.3, 1.5) |
| Reference: 35+ years | ||||
| Race/Ethnicity | ||||
| African American | 1.6 | (1.4, 1.9) | 1.6 | (1.4, 1.9) |
| Hispanic | 1.6 | (1.5, 1.8) | 1.5 | (1.4, 1.7) |
| Asian | 1.5 | (1.2, 1.8) | 1.5 | (1.2, 1.9) |
| American Indian/Native Alaskan |
1.4 | (1.0, 1.8) | 1.4 | (1.0, 1.9) |
| Other | 1.4 | (1.2, 1.6) | 1.3 | (1.1, 1.5) |
| Reference: White | ||||
| BAC Group | ||||
| .001 - .079 | 1.5 | (1.4, 1.6) | 1.3 | (1.2, 1.4) |
| .08+ | 1.3 | (0.9, 1.9) | 1.2 | (0.9, 1.7) |
| Reference: Zero BAC | ||||
| Time of the Day | ||||
| Nighttime | 1.5 | (1.3, 1.6) | 1.2 | (1.1, 1.4) |
| Reference: Daytime | ||||
| Trip Origination | ||||
| Bar/tavern/club | 2.1 | (1.8, 2.4) | 1.8 | (1.6, 2.1) |
| Restaurant/eating place | 1.2 | (1.0, 1.5) | 1.1 | (0.9, 1.3) |
| Someone else’s home | 1.1 | (1.0, 1.2) | 1.0 | (0.9, 1.1) |
| Work | 0.7 | (0.6, 0.9) | 0.7 | (0.6, 0.8) |
| Other | 1.0 | (0.9, 1.2) | 1.0 | (0.9, 1.2) |
| Reference: Home |
NOTE: The sample size was reduced from 8922 to 8838, because some drivers did not answer all the questions on their characteristics and were excluded from analyses.