A national survey has found that after a long, slow downward trend alcohol-impaired driving has recently increased significantly. From 1993 to 1997 the estimated annual number of episodes of alcohol-impaired driving (AID) declined at a rate of a little more than one percent per year, from 123 million to 116 million. From 1997 to 1999, however, it increased 37 percent, from 116 million to 159 million. It stayed at that increased rate in 2002.
The survey, published in the May issue of the American Journal of Preventive Medicine, also found that four out of five episodes of alcohol-impaired driving were reported by people who also reported binge drinking, defined as consuming five or more drinks or more than one occasion.
"After years of gentle steady progress in the 1990s we are now heading in the wrong direction," said Kyran Quinlan, MD, MPH, clinical associate in pediatrics at the University of Chicago, who worked with colleagues at the Centers for Disease Control and Prevention (CDC) on this report. "This tells us that we urgently need new strategies to prevent alcohol-impaired driving with special emphasis on reducing binge drinking."
"This is not just a statistical bump or noise in the data," he added. "This is a true behavioral change."
The authors point out that motor vehicle accidents are the leading cause of death in the United States for people between the ages of 1 and 34. Thirty percent of Americans will be involved in an alcohol-related crash in their lifetimes. Such accidents cause damages worth more than $50 billion a year.
"Deaths from alcohol-related crashes had been declining for years," added Quinlan, "but around 1999 they stopped going down, despite safer cars and highways."
The researchers, all based at the time at the CDC, analyzed telephone surveys with more than 100,000 people in the United States in 1993, 1995, 1997, 1999 and 2002. Respondents, aged 18 or older, were asked about their drinking habits, especially binge drinking. Those who did drink alcohol were asked: "During the past month, how many times have you driven when you've perhaps had too much to drink?"
People who reported binge drinking were 13 times more likely to report driving while alcohol impaired. Most binge drinkers reported that they often consume far more than five drinks per binge.
"The increase in alcohol-impaired driving episodes," the authors conclude, "is probably due, at least in part, to the substantial increase in binge drinking episodes… Indeed, prevention efforts in the United States are likely to be of limited success unless they are couple with efforts to also reduce the prevalence of binge drinking."
They also warn that their approach probably underestimates the magnitude of the problem. Many survey subjects, even though their identity remains confidential, are reluctant to admit that they drive while under the influence of alcohol. Those who do drink and drive tend to deny the impact of alcohol on their driving skills. Also, the survey did not include drivers under the age of 18, who have below-average driving skills and above-average use of alcohol.
The authors suggest renewed efforts to deter alcohol-impaired driving, such as lowering the legal blood-alcohol levels, prompt suspension of a driver's license for people arrested for AID, sobriety checkpoints, alcohol-ignition interlock programs and sustained public education. They also call for greater efforts to reduce binge drinking.
"Our study confirms what we were beginning to suspect and dreading to learn," said Quinlan, "that this is a huge problem and we are losing ground."
Additional authors of the study include Robert Brewer, Paul Siegel, David Sleet, Ali Mokdad, Ruth Shults and Nicole Flowers of the Centers for Disease Control and Prevention, which funded the research.