Under-estimation of Alcohol Consumption among Women At-risk for Drinking during Pregnancy

This study adds to a growing literature showing that definitions for "standard drinks" are often difficult to conceptualize and that people often underestimate their actual drink sizes. As part of an intervention aimed at reducing negative neonatal and maternal outcomes, insured at-risk women were asked to identify the vessels from which they drank each of 6 beverages (n=266). We calculated differences between their actual and standard drink sizes. Additionally, differences were compared to those reported in an earlier study of uninsured inner city minority women that used identical vessels methodology. Over half of the spirits, fortified wine and malt liquor drinkers underestimated the actual number of ounces their drinks contained. Most spirits drinkers (90%) and approximately three-quarters of the wine and malt liquor drinkers drank larger-than-standard drink sizes, with the median drink size 1.5 to 2.0 times larger than the standard size for those beverages. Heavier drinkers (>/=3 drinks per sitting) were more likely than lighter drinkers to underestimate their drink sizes. Findings were similar to those in the previous study using identical drink size measurements. Accurately assessing true drink sizes is underscored when the social, health and epidemiologic consequences associated with miscalculation are considered.