Long-term impact on alcohol-involved crashes of lowering the minimum purchase age in New Zealand.
OBJECTIVE
We assessed the long-term effect of lowering the minimum purchase age for alcohol from age 20 to age 18 years on alcohol-involved crashes in New Zealand.


METHODS
We modeled ratios of drivers in alcohol-involved crashes to drivers in non-alcohol-involved crashes by age group in 3 time periods using logistic regression, controlling for gender and adjusting for multiple comparisons.


RESULTS
Before the law change, drivers aged 18 to 19 and 20 to 24 years had similar odds of an alcohol-involved crash (P = .1). Directly following the law change, drivers aged 18 to 19 years had a 15% higher odds of being in an alcohol-involved crash than did drivers aged 20 to 24 years (P = .038). In the long term, drivers aged 18 to 19 years had 21% higher odds of an alcohol-involved crash than did the age control group (P ≤ .001). We found no effects for fatal alcohol-involved crashes alone and no trickle-down effects for the youngest group.


CONCLUSIONS
Lowering the purchase age for alcohol was associated with a long-term impact on alcohol-involved crashes among drivers aged 18 to 19 years. Raising the minimum purchase age for alcohol would be appropriate.
Taisia Huckle and Karl Parker are with the Social and Health Outcomes Research and Evaluation and Whariki Research Centre, School of Public Health, Massey University, Auckland, New Zealand.
Taisia
T
Huckle
Karl
K
Parker
D000063:Accidents, Traffic / Q000517:prevention & control / Q000706:statistics & numerical data*; D000293:Adolescent; D000367:Age Factors; D000428:Alcohol Drinking / Q000009:adverse effects / Q000331:legislation & jurisprudence*; D001334:Automobile Driving / Q000331:legislation & jurisprudence; D005260:Female; D006801:Humans; D008297:Male; D009520:New Zealand; D055815:Young Adult