What Is Moderate Drinking?

Alcohol Research & Health, Wntr, 1999 by Mary C. Dufour

In diary methods, participants record each drink consumed over a given timeframe (e.g., 1 week), ideally shortly after consumption. Researchers have recently introduced an automated variation of the diary method. In this approach, participants report their daily alcohol intake by calling a dedicated toll-free number and activating, through a touch-tone telephone, an automated, interactive voice-simulation system (Searles et al. 1995).

In summary, the five types of assessment instruments just described yield highly diverse data. For example, the assessed timeframe can range from the past 24 hours to the drinker's lifetime. Similarly, the questions may assess general alcohol consumption or the individual consumption of specific beverage types (e.g., beer, wine, or spirits). The specific wording of questions also may vary among studies. Survey findings indicate that the more specific and detailed the questions are, the higher the reported consumption. Finally, the surveys may vary in scope: Some surveys may address only alcohol consumption, whereas other surveys may assess all food and other nutrient intake, as well as additional health-related behaviors (e.g., smoking and exercise), and include only a few alcohol-specific questions.

Why are the differences among assessment instruments relevant to the discussion of moderate drinking? One reason is that for a given drinker, different questionnaires may elicit different responses and therefore lead to varying estimates of alcohol consumption for that person. Furthermore, even if a respondent provides identical answers, differences in the scientific assumptions and calculations associated with the survey methods may produce variations in the reported results. Studies comparing the results obtained with different assessment methods have noted many differences in findings, including the following (Rehm 1998).

Questionnaires using the graduated frequency approach consistently produce higher estimates of volume of alcohol consumption than do QF measures, particularly among heavier drinkers. One of the reasons underlying higher estimates with graduated frequency measures is that such measures generally involve more questions than do simple QF measures, particularly for heavier drinkers. Survey researchers have discovered that more questions (and consequently more answers) may lead to higher consumption estimates, which are generally considered to be more accurate.

Diary methods produce higher estimates than do either QF or short-term recall methods. For example, in the previously mentioned study using an automated interactive telephone reporting system (Searles et al. 1995), 50 volunteers reported their daily alcohol intake for 112 consecutive days. Other data collected by traditional means immediately after study completion demonstrated that drinkers - particularly heavier drinkers - retrospectively underreported their alcohol consumption.

More detailed and specific questions also elicit higher estimates of alcohol consumption. For example, separate QF questions for different periods within a given timeframe (e.g., each month within the past year) produce higher estimates than does one global QF question (e.g., consumption during the entire year). Similarly, beverage-specific questions or questions asking for consumption in different contexts (e.g., in bars, at home, or at parties and celebrations) produce higher estimates than do global questions asking about total alcohol consumption.