Addictive Behaviors, Vol. 16, pp. 555-560, 1991 Printed in the USA. All rights reserved.

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BRIEF REPORT

ALCOHOL CONTENT VARIATION IN THE ASSESSMENT OF ALCOHOL CONSUMPTION

CHRISTOPHER S. MARTIN and TED D. NIRENBERG Brown University and Substance Abuse Treatment Center,

Roger Williams General Hospital, Providence, Rhode Island

Abstract - Most investigators have not adequately accounted for the alcohol content of different beverages when assessing alcohol consumption. Considerable research has assessed consumption in terms of the number of standard drinks. A problem with standard drink measures is that differ- ent distilled spirits, wines, and malt beverages vary considerably in alcohol content. State-to-state and brand-to-brand variations in the strength of different malt beverage brands are provided, as malt beverage alcohol contents are not contained on labels due to federal and state regulations. Ignoring alcohol content variation when estimating consumption can produce a large amount of error. Alcohol consumption should be assessed in terms of the number, size, and alcohol content of beverages.

INTRODUCTION

The effects of alcohol consumption on health and responses to alcoholism treatment have been major issues in the alcohol field. While it is widely acknowledged that chronic heavy use adversely affects health (Turner, Mezey, & Kimball, 1977a, 1977b), the effects of more moderate levels of consumption are less clear (Popham & Schmidt, 1978). To as- certain the differential effects of varying levels of consumption, it is essential to have valid and reliable measures that can accurately detect alcohol consumption in a given time period.

Assessment of alcohol consumption is complicated by the fact that the major classes of alcoholic beverages have different concentrations of alcohol and are usually consumed in different volumes. This issue has been addressed by reference to the concept of alcohol equivalency. Alcohol equivalency refers to the fact that drinks that differ in alcohol con- tent are usually consumed in different volumes, such that the total amount of absolute alcohol consumed is similar for a typical drink of distilled spirits (e.g., gin, rum, whis- key), wine, and malt beverages (e.g., beer, ale, malt liquor). Thus, many researchers have assessed the number of standard drinks consumed by subjects in measures of the quantity of consumption (Sobell, Sobell, & Nirenberg, 1988).

Many different definitions of the standard drink measure have been used in the litera- ture. These definitions specify both the amount and alcohol content of malt beverage,

The authors thank the following institutions for providing information used in the preparation of this article: Virginia Department of Alcoholic Beverage Control; Bureau of Alcohol, Tobacco, and Fii; Health Educa- tion Foundation; Alcoholic Beverage Medical Research Foundation; Beer Institute; Anheuser-Busch, Inc.; Coors Brewing Company; G. Heileman Brewing Company, Inc.; Miller Brewing Company. Thanks also to Professor Robert Borkenstein and Drs. Fred Ellis and Dwight B. Heath.

Parts of this manuscript were presented as a poster session at the joint meeting of the Research Society on Alcoholism and the Inte.mational Society for Biomedical Research on Alcoholism in Toronto, Canada, June 17-22, 1990.

Requests for reprints should be sent to Dr. Christopher Martin, Center for Alcohol and Addiction Studies, Brown University, Box G, Providence, RI 02912.

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556 CHRISTOPHER S. MARTIN and TED D. NIRENBERG

wine, and distilled spirits that contain the same or similar amount of absolute al- cohol.’ In the United States, these absolute alcohol values range from 0.4 to 0.6 oz of absolute alcohol, with most falling close to 0.5 oz of absolute alcohol (e.g., Brandsma, Maultsby, & Welsh, 1987; Sobell, Sobell, Maisto, & Cooper, 1987; Sobell, Sobell, & Nirenberg, 1988).

Researchers should be aware of a major methodological issue in the use of standard drink measures. Alcohol content varies widely within the major classes of alcoholic bev- erages. Because standard drink definitions assume some typical alcohol content value in defining standard units (e.g., that malt beverages contain 4% alcohol), actual consump- tion may be overestimated for subjects who drink beverages with lower concentrations of alcohol and underestimated for subjects who drink beverages with higher concentrations of alcohol. Therefore, it is more accurate to measure the actual alcohol content of bever- ages when estimating alcohol consumption.

ALCOHOL CONTENT OF DIFFERENT BEVERAGES

There is a large amount of variation in the alcohol content of different brands of dis- tilled spirits and wine (Leake & Silverman, 1971). It is easy to determine the alcohol content of such beverage brands, because these values are given on bottle labels. Com- mercially available distilled spirits vary from 95% alcohol to 40% alcohol and to 20% alcohol if liqueurs such as schnapps are included in this category. The alcohol content of wine varies from about 8% to 14% alcohol. Fortified wines, made by adding alcohol to wine, vary from about 15% to 25% alcohol.

Alcohol content for malt beverages varies widely by country, by state in the United States, and by brand. Many countries have regulations concerning the permissible alcohol content of malt beverages. There are three classes of malt beverages in Sweden defined by ranges of alcohol content: Class I, 2.25% maximum; Class II, 3.5% maximum; Class III, 5.6% maximum. In Norway, Class I malt beverages have a maximum alcohol content of 2.5%, Class II have a maximum of 4.75%, and Class III have a maximum of 7.0%.

In the United States, it is difficult to obtain information concerning the alcohol content of different malt beverage brands. Federal regulations prohibit alcohol content inforrna- tion about malt beverages in advertisements and on labels, except where required by state law (Federal Alcohol Administration Act, sections 205[e] and 205[fj). Current state laws apply only to beers that have 3.2% alcohol by weight (4% by volume) or less. In these cases, labeling does not give exact alcohol content, but instead simply certifies that the alcohol content of the beverage does not exceed 3.2% alcohol by weight.

State-to-state variation Personal communication from several major U.S. brewers indicates that to comply with

state laws, a malt beverage brand will often have a different alcohol content in different states in the United States. There is a good deal of variation between states concerning the maximum allowable alcohol content of malt beverages (Modem Brewery Age, 1990). State laws concerning maximum allowable alcohol content are summarized in Table 1.

These state-to-state variations are complex. In some states, malt beverages can be over the allowed maximum if they are sold in liquor stores. In other states, malt beverages are

‘Alcohol content is usually expressed in the United States as percent alcohol by weight for malt beverages, as percent alcohol by volume for wines, and as proof spirits for hard liquor. Proof spirits is exactly twice per- cent alcohol by volume. For malt beverages, percent alcohol by weight is approximately 20% less than percent alcohol by volume. In this article, the alcohol content of different beverages is given as percent alcohol by volume for purposes of comparability, unless otherwise noted.

Alcohol content variation 557

Table 1. Summary of some 1990 state laws concerning maximum allowable alcohol content of malt beverages.

Maximum Content

4% alcohol

KatiSas Missouri Oklahoma Utah

5% alcohol

Alabama California Iowa Mississippi Oregon Texas

6% alcohol

Georgia Louisiana Vermont West Virginia

6.25% alcohol

Arkansas Iowa South Carolina Tennessee Wisconsin

7.5% alcohol

Idaho North Carolina Ohio South Dakota

8.75% alcohol

Montana

10% alcohol

Washington

15% alcohol

Massachusetts

Values are expressed as percent alcohol by volume. Some states have different regulations for ale, malt liquor, or beverages sold in liquor stores; some states have higher taxes and/or licensing fees for malt beverages that are above the maximum.

allowed to be over the maximum value but are then subject to higher taxes and/or licens- ing fees. Some laws concerning maximum content are for beverages that are called beer; higher content is allowed for malt beverages that are called malt liquor or ale. State laws use both the percent by weight and the percent by volume metrics. Clearly, researchers need to be familiar with regulations concerning the alcohol content of malt beverages in the area in which data on consumption are collected.2

Brand-to-brand variation There is a significant amount of variation in alcohol content among malt beverage

brands. Data concerning alcohol content of different brands were obtained from two sources. The first source was several major United States brewers; the second was the Virginia Department of Alcoholic Beverage Control, which has performed chemical tests

*Information about the alcohol beverage control laws of different states can be obtained from “Attention: state Laws,” Health Education Foundation, Suite 452, 600 New Hampshire Ave., N.W., Washington, DC 20037. The cost is $5 per state.

558 CHRISTOPHER S. MARTIN and TED D. NIRENBERG

on malt beverages seized during alcohol-related arrests. Alcohol content values were in close agreement when reported by both of these sources.

The alcohol contents of some low-alcoholsbeers, light beers, regular beers, and malt liquors/ales are presented in Table 2, along with ,medians and means for the brands within each category. These alcohol content values are provided as examples and not as a defini- tive guide, since these values may vary over time and do not apply where they are pro- hibited by state law.3

The alcohol content of these malt beverages varies almost sixfold from low-alcohol beers to certain imported malt liquors. If low-alcohol beers are excluded, the Mariation from some light beers to some imported malt liquors is approximately threefold. Low- alcohol beers usually contain between 2% and 2.5% alcohol; light beers between 3.5% and 4.3% alcohol; regular beers between 4.2% and 5.2% alcohol; and malt liquors and ales between 5.0% and 7.5% alcohol, with some imports substantially higher.

Within-brand variation Variations also occur within a brand in the same area. For example, alcohol content

testing data provided by the Virginia Department of Alcoholic Beverage Control indicate that the alcohol content of a major light beer increased from 3.5% to 4.1% in Virginia during 1988. This information is consistent with data provided by a major U.S. brewer, which document a similar increase for that brand in the Chicago area during 1988. Thus, information about the alcohol content of malt beverages will have to be updated as long as this information is not available on beverage labels or in advertising.

IMPLICATIONS OF VARIATIONS IN ALCOHOL CONTENT FOR THE ASSESSMENT

OF CONSUMPTION PRACTICES

Differences in alcohol content within these general classes of alcoholic beverages have important implications for the assessment of consumption. Researchers should use infor- mation about the alcohol content of different alcoholic beverages to better assess the amount of alcohol consumed. This information can easily be combined with information about the number and size of alcoholic beverages to estimate the volume of alcohol con- sumed in a given period of time.

Alcohol content can be integrated into current assessment methodologies. In research using the time-line follow-back (Sobell, Maisto, Sobell, & Cooper, 1979; Sobell et al., 1987) or other quantity/frequency assessment methods (Cahalan, Cisin, & Crossley, 1969; Polich, Armor, & Braiker, (1981), investigators should ask subjects about the brands of distilled spirits, wines, and,malt beverages that they have consumed. If subjects cannot remember the specific brands of beverages, researchers should still assess the type(s) of hard liquor, wines, and malt beverages typically consumed (e.g., light beer vs. regular beer vs. malt liquor). These reports would then be combined with measures of the num- ber and size of drinks to yield more precise estimates of the quantity of alcohol con- sumed. Such strategies have been partially employed in the literature. Polich and Orvis (1979) had subjects report whether they consumed regular or fortified wines and used different alcohol content values (12% and 18%) to compute quantity estimates. This ap- proach can be extended to malt beverages using the type of information contained in Table 2.

‘Researchers can contact breweries about the alcohol contents of their products. A list of the names and addresses of U.S. breweries is available from the Bureau of Alcohol, Tobacco, & Firearms, Distribution Center, 7943 Angus Court, Springfield, VA 22153. Request publication ATF 5100.13.

Alcohol content variation 559

Table 2. Percent alcohol by volume of different malt beverage brands.

Category Brand Alcohol content

(%)

Low-alcohol beers

Light beers

Regular beers

Malt Liquors/Ales

Old Style L.A.’ Anheuser-Busch L.A.’ Black Label L.A.b Lone Star Lightb Amstel Lightb Old Style Light’ Carl&erg Light’ Coors LinhF OlympiaLightb Budweiser Light’ Lowe&au Lrght’ Michelob Light’ Miller Lite’ Milwaukee’s Best Lightb Natural Light’ Stroh’s Lightb Pabst Lightb Schmidt’s Ligh? Pilsner UrouelP Milwaukee’s Bestb Schae.fe@ Anchor Steamb Black Labelb Blat.? CoOrSa Meister Brau* Schmidt’sb Stroh’sb Busch’ Dos Equisb Lone Starb Miller High Life’ Miller Genuine Draft’ Rainier’ Pabs? Rolling Rockb Budweiser’ Olympiab San Miguelb Old Style’ Michelob’ Michelob Dark’ Heineke# Lowenbrau’ Lowenbrau Dark’ Moosehead Beep Special Export’ Becksb Carlsberg~ Michelob Dry Old Style Dry’ Harley-Davidson Heavy Bee? Labatu SO Al@ M&on Al@ Colt 45 Malt Liquoe Schlitz Malt Liquop Magnum Malt Liquof King Cobra Malt Liquor’ Young’s London Aleb Schooner Doppelbock” Golden Hawk Malt Liquo? Elephant Malt LiquoZ Rainier Ale’ Dortmunder Unionb EKU 28 Malt Liquorb Samichlaus BieP

2.2 2.3 2.4 3.5 3.6 4.1 4.1 4.1 4.1 4.2 4.2 4.2 4.2 4.2 4.2 4.2 4.3 4.3 4.2 4.4 4.4 4.5 4.5 4.5 4.5 4.6 4.6 4.6 4.7 4.7 4.7 4.7 4.1 4.7 4.7 4.7 4.8 4.8 4.8 4.9 4.9 4.9 4.9 4.9 4.9 4.9 4.9 5.0 5.0 5.0 5.0 s.2 s.0 5.0 5.6 5.8 5.9 6.0 6.1 6.2 6.5 7.0 7.2 1.3 10.9 11.5

Mean = 2.3% Median = 2.3%

Mean = 4.1% Median = 4.2%

Mean = 4.74% Median = 4.7%

Mean = 6.85% Median = 6.15%

Values have been rounded in some cases, and apply where they are not prohibited by state. law. Data from brewing company. data obtained from Virginia Department of Alcoholic Beverage Control.

560 CHRISTOPHER S. MARTIN and TED D. NIRENBERG

Clearly, the need for more accurate measures of alcohol consumption depends on the research question(s) that are under consideration. The present suggestions may not be necessary for research in which more precise alcohol consumption measures are not needed. Nevertheless, the error produced by using the concept of a standard drink is po- tentially substantial as well as nonrandom. For example, if a standard drink definition is a 12-0~ malt beverage with 4% alcohol, consumption will be overestimated by almost one half for subjects who drink low-alcohol beer with 2.2% alcohol, and will be underesti- mated by more than 40% for subjects who drink malt liquor with 7% alcohol. This would produce substantial error in estimates of the quantity of alcohol consumed. The error would be especially large for heavy drinkers and for estimates over a long period of time.

In summary, standard drink definitions that specify alcohol content for a given bever- age type can limit the accuracy of data on the quantity of alcohol consumption, and may produce systematic underestimation or overestimation depending on the type of beverages typically consumed by different populations. Information about alcohol content should be integrated with information about the size and number of beverages to yield more accu- rate measures of the quantity of alcohol consumption.

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