In the U.S., a standard drink is usually defined as the equivalent of 0.6 ounces (17.74 ml.) of pure alcohol. The corresponding standard sizes are, generally, 12 ounces (355 ml.) of beer, five ounces (148 ml.) of wine, and 1.5 ounces (44.4 ml.) of spirits. A recent study of American drinkers that measures their usual alcohol consumption in the home environment has found considerable variation in drink size, particularly for spirits and wine. Results are published in the November issue of Alcoholism: Clinical & Experimental Research.
"Individual drinkers should be concerned with varying drink alcohol content because the consumption of non-standard drinks affects their ability to keep track of how much alcohol they have consumed and therefore their ability to conform to safe drinking guidelines and driving laws," said William C. Kerr, a scientist with the Alcohol Research Group at the Public Health Institute and corresponding author for the study.
"Without valid and reliable measures of how much alcohol is being consumed by a population, the ability to assess risk is compromised," added Lorraine Midanik, a professor in the school of social welfare at the University of California at Berkeley, and an affiliate senior scientist with the Alcohol Research Group. "Population estimates of alcohol use derived from self-reports are used to determine risk for various adverse health and social outcomes. Population estimates of alcohol use also help us to understand trends in the U.S. population. That is, 'are people drinking more, less or about the same alcohol