[The "standard drink unit" as a simplified record of alcoholic drink consumption and its measurement in Spain].
BACKGROUND
The use of a drink units' system is recommended in order to facilitate the registration and monitoring of alcohol consumption and to provide comparable data. A unit would be the alcohol content in defined volumes of different beverages with a standard strength. The value attributed to this drink unit varies from country to country and is questionable from a scientific viewpoint. This study provides research for defining the standard drink unit (SDU) for Spain.


METHODS
Two studies were designed for ascertaining the pure alcohol content of bulk drinking at home and in public places, taking into account available information on production, distribution of consumption and beverages strength. Eight Spanish regions, each one with 3 cities of respectively < 10,000, 10,000-100,000 and > 100,000 inhabitants, participated in the study. 10,751 observations were carried out and alcohol content was calculated for a standard drink of beer, wine and spirits.


RESULTS
Because of the great dispersion of volumes within each type of consumed beverages, none of the consumption curves presented a normal distribution. This feature level is to calculate its pure alcohol equivalence by means of the recorded median volume. Thus, SDU was found to be 10.09 g for wine, 9.1 g for beer and 19.82 g for spirits.


CONCLUSIONS
Global SDU would contain about 10 g of pure alcohol (= 1 beer o 1 glass of wine or a half measure of spirits). The calculation of alcohol consumption in drink units facilitates clinical records, epidemiological surveys and preventive messages.
D000428:Alcohol Drinking / Q000453:epidemiology*; D000434:Alcoholic Beverages / Q000706:statistics & numerical data*; D003625:Data Collection / Q000379:methods / Q000706:statistics & numerical data; D006801:Humans; D012959:Socioeconomic Factors; D013030:Spain / Q000453:epidemiology; D018709:Statistics, Nonparametric