The proportion of Australians drinking 20 or more standard drinks in a single session has grown in the last decade, and the amount the heaviest drinkers are consuming annually is also on the rise, a new study has shown.
The growth in very serious heavy drinking may help explain a recent rise in alcohol-related hospital admissions and liver cirrhosis at a time when the amount drunk by most Australians has remained steady or declined, the co-author of the study said.
The new study was authored by Michael Livingston, Post-Doctoral Research Fellow at the University of New South Wales' National Drug and Alcohol Research Centre (NDARC) and its findings will be presented at the NDARC Annual Research Symposium today.
The study was based on data collected on around 100,000 people aged 14 and up over the decade spanning 2001 to 2010. The group studied was representative of the general population.
The proportion of people who reported drinking 20 or more standard alcoholic drinks in a single session at least once in the last 12 months went up from 9% to 10.5% between 2001 and 2010, said study author Dr Livingston.
"So an extra 1.5% of the population is doing that very serious heavy drinking now than were 10 years ago. For what we define as "risky drinking"—that's drinking five or more standard drinks in a single session—there's 3% fewer doing that now than there were 10 years ago," he said.
The top 5% of the population in terms of heavy drinking are consuming 5% more alcohol than they were a decade ago.
"And the amount of alcohol drunk by the top 10% of the population in terms of heavy drinking has gone up by about 90 standard drinks extra per per person year, while the amount drunk by the rest of the population has gone down," said Dr Livingstone.
This study found that "evidence of increases in drinking among the heaviest drinkers offset by declining drinking across the remainder of the population. These findings provide some support for polarisation of consumption and suggest the need for policy interventions aimed particularly at the heaviest drinkers in society."
Dr Livingston said the results showed relatively small shifts in drinking trends and, while statistically significant, may represent "noise" in the data.
"But they are interesting and go against a lot of what we think we know. The basic tenet of alcohol research is that when there are shifts in drinking trends, everyone changes in the same direction," he said.
"However, given what we also know about increasing rates of harm and steady rates of per capita consumption, this might be part of the reason why we are seeing liver cirrhosis and emergency room presentations going up while our level of drinking across the population is showing no real increases," said Dr Livingston.
"I think what it implies is we need to think about interventions that focus on heaviest drinkers rather than just the whole population. That might include brief interventions with GPs or with medical professionals when these people present to hospital."