Drinking, disease and death

“Europeans are the world’s biggest boozers,” reported the Daily Mirror , which said that we typically drink 21.5 units of alcohol a week, nearly twice the global average. According to the news, new research has found that 10% of deaths in Europe can be attributed to drinking alcohol.

Behind the reports of today’s figures is a large study, conducted in conjunction with the World Health Organization, which seeks to estimate the global burden of alcohol-related disease, injury and death. It is the first in a series of articles that will be published in The Lancet medical journal about alcohol and global health.

Studies of this scale always have limitations as they rely on diverse data sources and methodologies, but the results do seem to reflect the patterns of alcohol consumption across different countries. The study makes very interesting reading as it looks at the extent to which alcohol is linked to many diseases and how it contributes to overall disease and disability, levels of which appear to increase in line with alcohol consumption levels.

Where did the story come from?

This research was conducted by Dr Jurgen Rehm and colleagues from the Centre for Addiction and Mental Health at the University of Toronto, the WHO Collaboration Centre for Substance Abuse in Zurich and other academic and medical institutions around the world. The study was funded by the WHO, the Swiss Federal Office of Public Health and the Centre for Addiction and Mental Health in Toronto. It was published in the peer-reviewed medical journal The Lancet.

What kind of scientific study was this?

This was a paper in which the authors estimated alcohol consumption and the prevalence of disorders linked to alcohol use through a review of published literature. They also identified other major diseases causally linked to alcohol and estimated what proportion of the burden of each disease is linked to alcohol consumption. The results were broken down by sex, age and global region. This publication is part of a series of papers about alcohol consumption.

Published research was used to estimate the prevalence of alcohol dependence in people aged between 18 and 64. The researchers also estimated the economic costs associated with alcohol consumption in selected countries through a review of relevant studies. Exposure data (data on alcohol consumption) was reported from the WHO Global Status Report on Alcohol (2004) and the WHO Global Information System on Alcohol and Health. Alcohol consumption data was also based on government records of sales of alcoholic drinks. Estimates of abstention (not consuming any alcohol) in the previous year and the volume of alcohol consumed per individual were taken from large surveys carried out in the countries since 2000.

The researchers created mathematical models to determine the effects of different quantities and patterns of drinking on injury and diseases. They were particularly interested in how alcohol affects death rates and quality of life. The years of healthy life lost to drink-related disability and the burden of disease in a population were calculated in terms of Disability Adjusted Life Years (DALYs).

The researchers applied various corrections to their models to adjust for harmful alcohol use and comorbidities, and made assumptions about the remission rate. While some diseases are wholly caused by alcohol, in other diseases and injuries alcohol is only a contributory factor.

The researchers established the diseases to which alcohol contributed using an accepted epidemiological theory of causality. They then established, for each of those diseases, how much burden could be attributed to alcohol across the countries, given their consumption patterns.

What were the results of the study?

The researchers concluded that, based on an assessment of the global literature, the average worldwide consumption is 6.2 litres of pure alcohol per adult per year, but that this varies widely across the world. A number of conclusions were drawn:

Eastern European countries around Russia consume the most alcohol, but other countries in Europe also consume a lot.
The average consumption in the WHO Europe Region is 11.9 litres of pure alcohol per adult per year.
The lowest consumption was seen in the WHO eastern Mediterranean region, which averaged 0.7 litres of pure alcohol per adult per year.
In low-income countries, consumption appeared to be linked to increasing income, but above a certain GDP (a measure of a country’s economic productivity), the relationship flattens out.
Men consumed more alcohol than women in all regions of the world.
Alcohol use is associated with high economic costs. In terms of US dollars adjusted for purchasing power in 2007, alcohol consumption costs governments between I$358 and I$837 per person per year.

What interpretations did the researchers draw from these results?

The researchers concluded that most adults across the world do not drink alcohol. Even so, alcohol consumption is common in many countries. The researchers have made a number of conclusions from their data analysis, including:

Globally, alcohol accounts for 4.6% of the global burden of disease and injury (7.6% for men and 1.4% for women).
Most of this increased disease and injury burden is seen in the 15 to 29-year-old age group.
An estimated 3.8% of all global deaths are attributable to alcohol.
This death rate varies widely across the world, with the highest rate in Europe where more than 10% of male deaths are attributable to alcohol.
Within Europe, the highest proportion of alcohol-attributable deaths are in countries of the former Soviet Union.
Preventable deaths are largely due to cardiovascular disease.

These mortality estimates have taken into account the observed beneficial effects of alcohol consumption. The researchers say that alcohol consumption is one of the largest avoidable risk factors for death. Poor populations and low-income countries have a greater burden of disease per unit of alcohol consumption than high-income populations.

What does the NHS Knowledge Service make of this study?

This large review and modelling study provides a fairly robust measure of the global impact of alcohol use and abuse across the world. The researchers discuss the limitations of their study, including limited data on alcohol consumption in some countries. In some cases, patterns of drinking were extrapolated from those seen in neighbouring countries. They estimate that 25% of global alcohol consumption goes unrecorded.

The study assessed the burden of chronic diseases attributable to alcohol, but did not include an assessment of infectious disease burden. The researchers note that several infectious diseases, including pneumonia and tuberculosis, have been linked to alcohol consumption. There has also been recent discussion about the role alcohol plays in the transmission of STIs because it can cause people to take more risks, a topic that was not addressed in this study.

Regardless of the limitations inherent in a large, global modelling exercise (which must rely on diverse data sources and methodologies), the results reflect the fact that patterns of alcohol consumption are linked to many diseases and the overall burden of injury.

In this enlightening research, the authors conclude that “we face a large and increasing alcohol-attributable burden at a time when we know more than ever about which strategies can effectively and cost-effectively control alcohol-related harms.” In the next paper in this series, they intend to discuss ways in which the burden can be reduced.