Although the prevalence of underage drinking has decreased since its peak in the late 1970s, drinking by youth has stabilized over the past decade at disturbingly high levels. The findings, part of a new analysis of youth drinking trends by researchers at the National Institutes of Health (NIH), appear in the September, 2004 issue of Alcoholism: Clinical and Experimental Research.
"While these data confirm the reduction in underage drinking rates since the 1970s, they also underscore the need to redouble our efforts against this important problem," says Ting-Kai Li, M.D., Director of the National Institute on Alcohol Abuse and Alcoholism at the NIH. "The authors have demonstrated an important means for monitoring long-term changes in alcohol use patterns that will serve us well in these efforts."
Since 1975, information about drinking by persons age 18 and younger has been collected by a number of ongoing national surveys, including the Monitoring the Future (MTF) study, the Youth Risk Behavior Survey (YRBS), and the National Household Survey on Drug Abuse (NHSDA). These surveys have shown that almost 80 percent of adolescents have consumed alcohol by the time they are 12th-graders, and that about 12 percent of 8th-graders have consumed five or more drinks on a single occasion within the past two weeks.
Although year-to-year differences in drinking patterns in these surveys are often statistically significant, such short-term comparisons provide little useful information about long-term trends, or changes in drinking habits over multi-year periods.
In the current study, researchers Vivian B. Faden, Ph.D., of the NIAAA, and Michael P. Fay, Ph.D., of the National Cancer Institute applied "joinpoint" statistical methodology to analyze trends in youth drinking data collected in three surveys: the MTF, the YRBS, and the NHSDA. Joinpoint analysis uses sophisticated statistical methodology to look at all available years of data from a survey simultaneously to identify significant changes in direction in trends.
"We applied this technique to three different surveys to see if joinpoint statistics tell the same story in terms of trends across surveys," explains Dr. Faden, Associate Director of NIAAA's Division of Epidemiology and Prevention Research. "This approach reveals information about trends in underage drinking heretofore unavailable, and strengthens the conclusions we draw regarding underage drinking trends."