Context In 1997, unintentional injury was the leading cause of death for persons
aged 1 to 34 years. Approximately one third of deaths due to unintentional
injury in the United States are estimated to be alcohol related. Onset of
drinking at an early age has been found to be associated with alcohol dependence,
but whether early-onset drinking increases risk for unintentional injury while
drinking is unknown.
Objective To explore whether persons who started drinking at an early age are
more likely to have experienced unintentional injuries while under the influence
of alcohol.
Design and Setting The National Longitudinal Alcohol Epidemiology Survey, a cross-sectional
survey conducted in 1992 of a representative sample of the US population.
Participants A total of 42,862 randomly selected adults (response rate, 90%; mean
age, 44 years).
Main Outcome Measures Unintentional injury involvement while under the influence of alcohol
by age of drinking onset (categorized as <14 years, each age from 14-20
years, or ≥21 years).
Results Relative to respondents who began drinking at age 21 years or older,
those who started before age 14 years as well as those who started at each
intervening age up to 21 years were significantly more likely to have been
injured while under the influence of alcohol, even after controlling for history
of alcohol dependence, heavy drinking frequency during the period that they
drank most, family history of alcoholism, and other characteristics associated
with earlier onset of drinking. After adjusting for these variables, odds
ratios for having been injured while under the influence of alcohol were as
follows: for younger than 14 years, 2.98 (95% confidence interval [CI], 2.29-3.89);
age 14 years, 2.96 (95% CI, 2.26-3.88); age 15 years, 3.14 (95% CI, 2.48-3.97);
age 16 years, 2.38 (95% CI, 1.90-2.98); age 17 years, 2.12 (95% CI, 1.66-2.71);
age 18 years, 1.33 (95% CI, 1.08-1.64); age 19 years, 1.42 (95% CI, 1.07-1.89);
and age 20 years, 1.39 (95% CI, 1.01-1.91).
Conclusion Drinking onset at ages younger than 21 years is associated with having
experienced alcohol-related injuries.
In 1997, 92,253 people died because of unintentional injuries, the leading
cause of death in the United States for persons aged 1 to 34 years.1 Of those deaths, 42,013 resulted from motor vehicle
crashes,2 and the balance from falls, drownings,
burns, and unintended gunshot wounds.
Alcohol consumption increases the likelihood that persons will be injured
while engaging in a variety of activities of daily living, including driving
a motor vehicle, walking, swimming, and boating.3-9
Nearly 40% of traffic deaths in the United States involve alcohol and at least
300,000 persons are injured annually in police-reported alcohol-related traffic
crashes.10 Thirty-one percent of persons who
died as a result of a nontraffic unintentional injury in 331 medical examiner
studies in the United States from 1975 to 1995 had blood alcohol levels of
0.10 or higher.9
A recent analysis of the National Longitudinal Alcohol Epidemiology
Survey (NLAES) found that age of drinking onset was strongly related to having
experienced alcohol dependence during one's life as defined by the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV) criteria,11 a finding previously reported
in smaller studies and those using the Diagnostic Interview Schedule and the Diagnostic and Statistical Manual of Mental Disorders, Third Edition criteria.12 Among both men and women
with and without a family history of alcoholism, persons who began drinking
regularly before age 14 years were at least 3 times more likely to experience
diagnosable alcohol dependence during their life than those who did not drink
until they were older than 21 years.
Alcoholism is the leading risk factor for injury.13
Alcoholism treatment,14 as well as programs
that systematically screen injured persons for alcoholism and offer them brief
intervention and referral to alcoholism treatment, can markedly reduce injuries.13 However, analyses of the NLAES survey also reveal
that nearly one third of persons injured under the influence of alcohol never
in their life met alcohol-dependence criteria. Early age of drinking onset
may be an indicator of increased risk of alcohol-related injury even among
persons who have not had diagnosable alcohol dependence. Questions in the
NLAES survey permit us to explore whether early age of drinking onset was
related to respondents drinking heavily, placing themselves in situations
that increased their risk of injury, and having experienced an unintentional
injury after drinking, even after controlling for alcohol dependence and other
personal characteristics associated with the age respondents started drinking.
The NLAES is a national probability survey sponsored by the National
Institute on Alcohol Abuse and Alcoholism. In 1992, the US Bureau of the Census
administered face-to-face interviews with 42,862 noninstitutionalized respondents
aged 18 years and older, mean age 44 years, residing in the 48 contiguous
states and the District of Columbia.
The multistage sampling approach used for NLAES has been described in
detail.15 Blacks and persons aged 18 to 29
years were oversampled, but the data were weighted in the analyses so that
the sample is representative of the US population. The household response
rate was 91.9% and the in-person response rate was 97.4%. The overall response
rate was 90%.
Measures of alcohol use and dependence were derived from the Alcohol
Use Disorder and Associated Disabilities Interview Schedule, a fully structured
diagnostic psychiatric interview designed to be administered by trained interviewers
who are not clinicians.
The Alcohol Use Disorder and Associated Disabilities Interview Schedule
included a sequence of questions that measure alcohol dependence based on
the criteria for alcohol dependence of the DSM-IV.
Diagnosis of alcohol dependence required that in any 1 year a respondent must
meet at least 3 of the following 7 criteria: (1) tolerance; (2) withdrawal
or avoidance of withdrawal; (3) persistent desire or unsuccessful attempts
to cut down or stop drinking; (4) spending a lot of time drinking, obtaining
alcohol, or recovering from its effects; (5) giving up or reducing occupational,
social, or recreational activities in favor of drinking; (6) impaired control
over drinking; and (7) continuing to drink despite a physical or psychological
problem caused or exacerbated by drinking. An independent test-retest study
determined good reliability with a κ of 0.76 and a κ of 0.73 for
past year and prior to past year dependence diagnoses, respectively.16
The age of drinking onset was ascertained by asking respondents who
had consumed at least 12 drinks in any year of their life how old they were
when they first started drinking, not counting small tastes or sips of alcohol.
In an independent test-retest study before the full NLAES was conducted, the
test-retest reliability of the drinking onset variable was good with a κ
of 0.72.16
In this study, a respondent was classified as family history positive
if any of their first-degree relatives (ie, parents, siblings, children) were
reported as having been alcohol dependent or abusers consistent with DSM-IV criteria. In a test-retest study, the family history
items showed good-to-excellent reliability with a κ at 0.72 for fathers,
1.00 for mothers, 0.90 for brothers, 0.73 for sisters, and 0.65 each for sons
and daughters.16
Current heavy drinking was determined by asking respondents: "During
the past 12 months, about how often did you have five or more drinks of any
type of alcohol in a single day?" Respondents were also asked: "About how
often would you say you usually drank enough to feel drunk during the last
12 months? By drunk, I mean times when your speech was slurred, you felt unsteady
on your feet or you had blurred vision." We also constructed a measure of
the frequency with which respondents drank 5 or more drinks during their period
of heaviest drinking in their life. Respondents were asked whether there were
periods in their life when they drank more than in the past year. Respondents
who answered yes were then asked their frequency of drinking and the amounts
they usually consumed on days they drank during this period. They were also
asked what was the greatest amount they drank on any day during that period
and how frequently they drank that amount. We used data from these questions
as well as questions about frequency of drinking 5 or more drinks in the past
year to determine their frequency of drinking 5 or more drinks during their
period of heaviest drinking.
Taking risks that might lead to injury was assessed by the following
questions, "In your life, did you ever get into a situation while drinking
or after drinking that increased your chances of getting hurt—like swimming,
using machinery, or walking in a dangerous area or around heavy traffic? Did
that happen in the past 12 months?" Lifetime and past year alcohol-related
injury involvement were explored by asking respondents: "In your entire life,
did you ever accidentally injure yourself under the influence of alcohol,
for example have a bad fall, or cut yourself badly, get hurt in a traffic
accident, or anything like that? Did this happen in the past 12 months?"
All statistical analyses were conducted using the SUDAAN statistical
package to account for the survey design.17
Age of drinking onset was categorized as younger than 14 years, each year
separately from 14 through 20 years, and 21 years or older (the minimum legal
drinking age throughout the United States). Analyses focused only on respondents
who currently drink and formerly drank and who responded to this question.
The significance of relationships between age of drinking onset and respondent
background characteristics was tested using χ2 analysis.
We examined the relationship between age of drinking onset and frequency
of heavy drinking, adjusting for background characteristics including history
of alcohol dependence through a series of multiple logistic regression analyses.
We examined the following outcomes as dichotomous variables: whether respondents
drank at least 5 or more drinks at least once per week in the past year; drank
to intoxication at least weekly in the past year; or drank 5 or more drinks
at least daily during the period when respondents drank most heavily. Odds
ratios and 95% confidence intervals were calculated describing the increased
risk of these outcomes for those with drinking onset before age 14 years and
at each age from 14 through 20 years relative to those who started drinking
at or after age 21 years.
To assess whether age of drinking onset was related to injury outcomes,
we also conducted multiple logistic regression analyses examining, as dichotomous
outcome variables, whether respondents ever or in the past year got into a
situation while or after drinking that increased their risk of injury; or
unintentionally injured themselves while under the influence of alcohol.
The regression analyses were conducted twice. First, we entered the
personal, social, and demographic characteristics associated with age of drinking
onset, excluding alcohol dependence and measures of heavy drinking frequency,
then we added measures of alcohol dependence and heavy drinking. This was
done to assess whether any relationships between age of drinking onset and
injury involvement were primarily a function of those who started drinking
earlier in life being more likely to experience more frequent heavy drinking
episodes.
We entered the frequency of heavy drinking during the respondent's heaviest
drinking period into the regression analyses examining lifetime exposure to
injury risk and involvement, and the past year frequency of heavy drinking
measures into the regression analyses examining past year exposure to injury
risk and injury involvement. For consistency across models, the entire set
of background variables was included in the analysis of each drinking and
injury outcome.
Respondent characteristics are listed in Table 1. Several subgroups in the study were significantly more
likely to have begun drinking at earlier ages: respondents who were male,
younger, never married, who had less than a high school education, who currently
or ever smoked or used illicit drugs, or who were currently or ever dependent
on alcohol, and respondents reporting a family history of alcoholism (all
relationships, P<.001; data available on request).
Frequent heavy drinking in the past year and during the period when
respondents drank most was associated with greater risk of injury involving
alcohol. To illustrate, 29% of respondents who drank to intoxication at least
weekly in the past year were in a situation that year after drinking that
increased their risk for injury compared with 3% of drinkers who never drank
to intoxication in the past year (P<.001). Seventeen
percent who drank to intoxication at least once per week in the past year
were injured under the influence of alcohol in the past year compared with
0.1% of drinkers who never drank to intoxication in the past year (P<.001).
Drinking Onset Age and Subsequent Drinking Practices
Respondents who began drinking at younger ages were much more likely
than those who did not start drinking until they were 21 years or older to
report heavy drinking both in the year prior to the survey and during their
period of heaviest drinking (Figure 1).
Those who started drinking prior to age 14 years were more than 3 times likely
to report consuming 5 or more drinks on a single day at least once per week
during the past year. They were 7 times more likely to report drinking enough
to be intoxicated at least once per week. Further, they were 3 times more
likely to report drinking 5 or more drinks at least once per week during their
period of heaviest drinking.
The regression analyses examining the relationship between age of drinking
onset and drinking behavior revealed that even after controlling for diagnosis
of alcohol dependence and other variables related to age of drinking onset,
the younger respondents were when they started drinking, the more likely they
were in the past year to drink 5 or more drinks on an occasion and to drink
to intoxication at least once per week (Table 2). Compared with those who began drinking at age 21 years
or older, those who began before age 14 years were nearly 1.4 times more likely
to drink 5 or more drinks and 2.8 times more likely to drink to intoxication
at least weekly in the past year. They were also 2.8 times more likely to
consume 5 or more drinks daily during their period of heaviest drinking during
their lifetime.
Drinking Onset Age and Subsequent Injury Risks
Early age of drinking onset was also strongly related to both being
in situations while or after drinking that increased a person's chances of
being injured and being injured while under the influence of alcohol. Compared
with respondents who began drinking at age 21 years or older, those who began
drinking prior to age 14 years were nearly 7 times more likely to report having
been in situations that increased their chance of injury ever in their lifetime
and in the past year (Figure 2).
Persons drinking prior to age 14 years were also 12 times more likely to have
ever been injured while under the influence of alcohol ever in their lifetime
and in the past year (Figure 3).
These relationships were generally monotonic from drinking age onset at age
14 years to age 21 years or older. The younger respondents were when they
began drinking, the more likely they were to have been in situations that
increased injury risk and to have been injured under the influence of alcohol.
The regression analyses on injury outcomes (not including alcohol dependence
and drinking measures) (Models 1A and 1B in Table 3 and Table 4)
revealed that even after controlling for other personal characteristics associated
with age of drinking onset, respondents who began drinking before age 14 years
relative to those who started at age 21 years or older were 4.8 times more
likely to have ever been in a situation after drinking that increased their
risk of injury and 2.4 times more likely to have done so in the past year.
They were also 4.9 times more likely to have ever been injured while under
the influence of alcohol and 3.2 times more likely to have been injured this
way in the past year. Even when we also included in the regression analysis
measures of alcohol dependence, frequency of drinking 5 or more drinks during
a respondent's period of heaviest drinking, and past year frequency of drinking
5 or more drinks or to intoxication (Models 2A and 2B in Table 3 and Table 4),
each of which were independently related to our study outcomes, those who
began drinking prior to age 14 years relative to those who started at 21 years
or older were 3 times more likely ever and 1.5 times more likely in the past
year to have been in a situation after drinking that increased their risk
of injury. They were also 3 times more likely ever and 2 times more likely
in the past year to have been injured while under the influence of alcohol.
Further, lifetime elevated injury risks were not confined to those who
began drinking before age 14 years. Persons who began drinking in each age
group younger than 21 years relative to those who started when they were 21
years or older were significantly more likely during their lives to have ever
been injured while under the influence of alcohol and to have placed themselves
in situations after drinking that increased their risk of injury. This was
found even after controlling for history of alcohol dependence, frequency
of heavy drinking during respondents' heaviest drinking period, and numerous
other characteristics related to age of drinking onset (Model 2A in Table 3 and Table 4).
Our analyses indicate that a large part, but not all, of the relationship
between early age of drinking onset and unintentional injury while under the
influence of alcohol in the past year resulted from those who began drinking
at an early age reporting more frequent heavy drinking in the past year. Persons
who began drinking in each age group 17 years and younger were significantly
more likely than those starting at age 21 years and older to have been injured
after drinking in the past year when we controlled for the initial set of
characteristics related to age of drinking onset (Model 1B in Table 4). However, after further adjusting for diagnosis of alcohol
dependence and for frequency of drinking 5 or more drinks on an occasion or
to intoxication in the past year, only those who began drinking prior to age
14 years were still significantly (2 times) more likely to have been injured
in the past year while under the influence of alcohol (Model 2B in Table 4).
Frequent heavy drinking in the past year, which is more common among
those who started drinking early in life, is particularly problematic given
the disproportionate willingness of people who began drinking early in life
to place themselves in situations after drinking that increase their risk
of injury (Table 3). Even after
controlling for measures of current alcohol dependence and past year frequency
of drinking 5 or more drinks or to intoxication, persons who began drinking
prior to age 18 years were also significantly more likely than those starting
at age 21 years or older to place themselves in situations after drinking
in the past year that increased their risk of injury (Model 2B in Table 3).
Strategies to delay the age persons begin drinking, such as the minimum
legal drinking age of 21 years, have been found to reduce drinking,18 alcohol-related traffic deaths,19
and deaths from other unintentional injuries among persons younger than 21
years.20 One study indicated that the law also
reduced drinking among persons 21 to 25 years who grew up in states with minimum
legal drinking ages of 21 years relative to other states,18
but the effect of the law on injury involvement during adult years was not
studied. Previous US studies have also indicated that the younger people are
when they begin drinking, the greater the likelihood they will experience
alcohol dependence during their lifetime.11,12
This report indicates that early age of drinking onset is associated
with frequent heavy drinking later in life not only for persons with diagnosable
alcohol dependence, but other drinkers as well. This, in turn, heightens the
risk of alcohol-related injuries for persons both when they are below and
above the legal drinking age of 21 years. Further, those who began drinking
at younger ages more often report placing themselves in situations after drinking
that increase risk of injury, not only when they are younger than 21 years,
but also as adults. This was found not only among respondents dependent on
alcohol and others who frequently drink heavily and to intoxication, but also
among other respondents who drink. Finally, persons who began drinking in
each age group younger than 21 years relative to those starting after age
21 years were significantly more likely during their lives to have been injured
while under the influence of alcohol. This was found even after controlling
for history of alcohol dependence, frequency of heavy drinking during respondents'
heaviest drinking period, and numerous characteristics related to age of drinking
onset.
We should caution that this study's results were based on self-report
in a cross-sectional survey, and hence may be subject to limitations associated
with self-report. On the one hand, social desirability biases may foster underreporting
of alcohol use and injury involvement after drinking. On the other hand, persons
willing to report heavy drinking may be less hesitant than others to report
injury involvement after drinking. Although the sample was nationally representative,
large, and the response rate was excellent, it would be useful to replicate
these results in a longitudinal study with chemical markers in addition to
self-report.
It is possible that people who engage in a variety of deviant or illegal
behaviors at an early age are more likely to continue them later in life.
For example, childhood conduct disorder has been associated with substance
abuse later in life.21 However, the relationships
between early drinking onset and recent heavy drinking and injury involvement
were independent of the current or past use of illegal drugs or tobacco.
Our findings indicate a need for additional research in 2 areas. First,
research is needed to explain why starting to drink at an early age relates
to alcohol dependence and to heavier drinking later in life, even among persons
who are not dependent. Genetics may play a role by predisposing certain individuals
to exhibit tolerance to the physiologic effects of alcohol early in their
drinking careers, thereby contributing to the establishment of heavier drinking
patterns that persist later in life.22 Familial
influences, both genetic and environmental, may account for the early onset/later
dependence relationship.23 Persons who drink
earlier may have physiologic changes that contribute to greater tolerance
and the need to drink more to achieve the same pleasurable sensations after
drinking. Persons who started drinking earlier in life may have learned to
drink in less controlled situations with peers whose drinking norms are to
drink to intoxication rather than with family and parents who might drink
more moderately. Also, persons who develop alcoholism later in life may have
had more adverse experiences in childhood such as psychological, physical
and sexual abuse, domestic violence, and substance abuse by parents.24 Drinking earlier and more heavily may be an attempt
to cope with these experiences.
Second, research needs to examine why, even when diagnosis of alcohol
dependence and measures of frequency of lifetime and past year heavy drinking
are controlled, persons who began drinking at an earlier age are more likely
after drinking to place themselves in situations that pose risk of injury.
Several explanations are possible. Those who begin drinking at an early age
may be less fearful of injury and situations that pose risk of injury. Some
may derive pleasure or a sense of self-esteem by taking risks associated with
injury. It is well-known that persons who drive after drinking, for example,
are more likely to speed and are less likely to wear seat belts.25
Alternatively, persons who start drinking at earlier ages may not be as aware
or appreciate how alcohol increases injury risk. Studies have shown that people
who drive after heavy drinking are more likely to believe they can drive safely
after higher amounts of alcohol consumption.26
They may believe for example the risk of traffic crashes and other injuries
increase only for people who are visibly intoxicated. Also, their heavier
consumption of alcohol may further impair the judgment of those who start
drinking at a younger age. After drinking, they may be less likely than when
sober to recognize situations that pose risk of injury or to fully appreciate
the risks posed by those situations.
While research needs to be done to determine whether delaying the onset
of drinking will prevent alcohol-related injury later in life, we think our
findings provide important information for physicians and other health care
providers to share with their adolescent patients about risks associated with
early age of drinking onset. They should explore the age their patients started
to drink and advise their patients that people who start drinking at early
ages not only have an increased risk of developing alcohol dependence, they
also have an increased risk of experiencing motor vehicle and other unintentional
injuries, which are the major causes of death among adolescents and young
adults. Recent national surveys indicate that after a decade of decline, the
percentage of high school seniors who drink, drink heavily, and drive after
drinking has increased in the past 2 years.27
The study reported here supports efforts to expand clinical, educational,
legal, and community interventions that delay onset of drinking.
1. Office of Statistics and Programming database. Hyattsville, Md: CDC National Center for Health Statistics; 1999.
2.National Highway Traffic Safety Administration. Traffic Safety Facts 1997. Washington, DC: US Dept of Transportation; 1998.
3.Zador PL. Alcohol-related relative risk of fatal driver injuries in relation
to driver age and sex.
J Stud Alcohol.1991;52:302-310.Google Scholar 4.Zador P, Krawchek S, Voas R. Alcohol-related relative risk of driver fatalities and driver involvement
in fatal crashes in relation to driver age and gender: an update using 1996
data.
J Stud Alcohol.2000;61:387-395.Google Scholar 5.Honkanen R, Ertama L, Kuosmanen P, Linnoila M, Alha A, Visuri T. The role of alcohol in accidental falls.
J Stud Alcohol.1983;44:231-245.Google Scholar 6.Hingson R, Howland J. Alcohol as risk factor for injuries and deaths due to falls: a review
of the literature.
J Stud Alcohol.1987;48:212-219.Google Scholar 7.Howland J, Hingson R. Alcohol as a risk factor for drownings: a review of the literature
(1950-1985).
Accid Anal Prev.1988;20:19-25.Google Scholar 8.Hingson R, Howland J. Alcohol and non-traffic unintentional injuries.
Addiction.1993;88:877-883.Google Scholar 9.Smith G, Branngs C, Miller T. Fatal non-traffic injuries involving alcohol: a meta-analysis.
Ann Emerg Med.1999;33:699-702.Google Scholar 10.National Highway Traffic Safety Administration. Traffic Safety Facts: Alcohol 1997. Washington, DC: US Dept of Transportation; 1998.
11.Grant B. The impact of family history of alcoholism on the relationship between
age at onset of alcohol use and
DSM-III alcohol dependence.
Alcohol Health Res World.1998;22:144-147.Google Scholar 12.Clapper R, Bulca S, Goldfield Z, Lipsett L, Tsuang M. Adolescent problem behaviors as predictors of adult alcohol diagnoses.
Int J Addict.1995;30:507-523.Google Scholar 13.Gentillelo L, Rivara F, Donovan D.
et al. Alcohol interventions in a trauma center as a means of reducing the
risk of injury recurrence.
Ann Surg.1999;230:473-483.Google Scholar 14.Dinh-Zarr T, Diguiseppi C, Heitman E, Roberts I. Preventing injuries through interventions for problem drinking.
Alcohol Alcohol.1999;34:609-621.Google Scholar 15.Massey JT, Parsons VL, Tadros W. Vital and Health Statistics Report Series 2(10):
Design and Estimation for the National Health Interview Survey, 1985-1994. Hyattsville, Md: National Center for Health Statistics, US Dept of
Health and Human Services; 1989.
16.Grant BF, Harford FC, Dawson DA, Chou PS, Pickering RP. The alcohol use disorder and associated disabilities interview schedule:
reliability of alcohol and drug modules in a general population sample.
Drug Alcohol Depend.1995;39:37-44.Google Scholar 17.Shah BV, Barnwell BG, Bieler GS. SUDAAN User's Manual, Release 7.0. Research Triangle Park, NC: Research Triangle Institute; 1996.
18.O'Malley P, Wagenaar A. Effects of minimum drinking age laws on alcohol use, related behavior
and traffic crash involvement among American youth.
J Stud Alcohol.1991;52:478-491.Google Scholar 19.General Accounting Office. Drinking Age Laws: An Evaluation Synthesis of Their
Impact on Highway Safety. Washington, DC: General Accounting Office; 1987.
20.Jones N, Pieper C, Robertson L. The effect of the legal drinking age on fatal injuries of adolescents
and young adults.
Am J Public Health.1992;82:112-114.Google Scholar 21.Robins LN. Childhood conduct problems, adult psychopathology and crime. In: Hodgins S, ed. Mental Disorder and Crime.
Newbury Park, Calif: Sage; 1993:173-193.
22.Shuckit M. New finding in the genetics of alcoholism.
JAMA.1999;281:1875-1876.Google Scholar 23.Prescott CA, Kendler KS. Age at first drink and risk for alcoholism: a non-causal association.
Alcohol Clin Exp Res.1999;23:101-107.Google Scholar 24.Felitti V, Anda R, Nordenberg D.
et al. The relationship of childhood abuse and household dysfunction to many
of the leading causes of deaths in adults.
Am J Prev Med.1998;14:245-258.Google Scholar 25.Hingson R, Howland J, Schiavone T, Damiata M. The Massachusetts saving lives program: six cities shift the focus
from drunk driving to speeding, reckless driving and failure to wear safety
belts.
J Traffic Med.1990;3:123-132.Google Scholar 26.National Highway Traffic Safety Administration. National Survey of Drinking and Drivers Attitudes
and Behavior. Washington, DC: US Dept of Transportation; 1996. Publication HS 808,438.
27.O'Malley PM, Johnston LD. Drinking and driving among high school seniors.
Am J Public Health.1999;89:678-684.Google Scholar