Actual and Perceived Units of Alcohol in a Self‐Defined “Usual Glass” of Alcoholic Drinks in England

Abstract

BackgroundSeveral studies have found participants pour more than 1 standard drink or unit as their usual glass. This is the first study to measure actual and perceived amounts of alcohol in a self-defined usual glass of wines and spirits in the general population.MethodsParticipants were a convenience sample of adults who drink alcohol or who pour drinks for other people (n = 283, 54% women) at 6 sites in South East England. The survey was face to face and comprised a self-completion questionnaire and pouring task. Estimation accuracy, categorised as correct (±0.5 units), underestimate (>0.5 units), or overestimate (>0.5 units) was the main outcome.ResultsThe mean number of units poured was 1.90 (SD 0.80; n = 264) for wine and 1.93 (SD 0.78; n = 201) for spirits. The amount of alcohol in a self-defined usual glass was estimated in 440 glasses (248 wine and 192 spirits). Overestimation took place in 42% glasses of spirit poured and 29% glasses of wine poured, and underestimation in 17 and 19%, respectively. Multinomial logistic regression found volume poured to be significantly associated with underestimating both wines and spirits, and additionally for wine only, belonging to a non-white ethnic group and being unemployed or retired. Not having a university degree was significantly associated with overestimating both drink types.ConclusionsThis study is the first in the general population and did not identify systematic underestimation of the amount of alcohol in a self-defined usual glass. Underestimation is significantly associated with volume poured for both drink types; therefore, advocating pouring smaller glasses could reduce underestimation of alcohol consumption.

The Economic Burden of Cancers Attributable to Tobacco Smoking, Excess Weight, Alcohol Use, and Physical Inactivity in Canada

“…Individuals either report fewer drinks than were actually consumed or are unaware of the amount of alcohol present in their drinks [31][32][33] . Over-pouring is also a common occurrence, particularly among college-aged adults 34 .…”

Estimates of the Absolute and Relative Strengths of Diverse Alcoholic Drinks by Young People

“…However, they did not look at between-drink differences, but the current data suggest that estimates vary with drink type, such that underestimates are most apparent for beers and wines. Recently, testing a convenience sample of N=283 UK adults in a pouring task, Boniface et al (2013) showed that the estimated unit contents of self-defined "usual" glasses of spirit and wine drinks were inaccurate by more than 0.5 units for 58% of spirit estimates and 48% of wine estimates. Overestimation of the unit contents of self-defined glasses of wine and spirits was more common than underestimation (beers were not tested), but interestingly the proportion of female underestimators was almost twice that of male underestimators, and a greater proportion of men than women were accurate; although these differences were not significant, the profile is consistent with the present results.…”

“…Similarly, De Visser & Birch (2012) reported that UK university students showed a poor understanding of the "unit" measurement and consistently underestimated the alcohol contents of common drinks; moreover they did not consider government intake guidelines to be useful. Boniface, Kneale, & Shelton (2013) also reported widespread inaccuracies in estimating the unit contents of self-poured drinks among a broader adult (non-student) sample. Perhaps more worryingly, a survey of 445 medical doctors in the UK county of Yorkshire in 2009 found that only 18% were "fully conversant" with the unit system, even though 79% claimed to be familiar with it, and only 68% correctly reported current medical guidelines for unit intake per week (Das, Corrado, Kyerematen, Smithson, & West (2009).…”

“…a 25 ml shot of spirits) and their own. Numerous studies in several countries have shown that people pour much more than the standard volumes in free-pour paradigms (Boniface Kneale, & Shelton, 2013;De Visser & Birch, 2012;Gill & Donaghy, 2004;Gill & O'May, 2007b;Gill, Donaghy, Guise, & Warner, 2007;Lemmens, 1994;White, Kraus, McCracken, & Swartzwelder, 2003;White et al, 2005). In studies by Gill and colleagues (Gill & Donaghy, 2004;Gill & O'May, 2007b;Gill, Donaghy, Guise, & Warner, 2007), volumes poured by participants were approximately double the size of standard bar measures for wine and spirits.…”

Moderate drinking before the unit: Medicine and life assurance in Britain and the US c.1860–1930

“…He warned that many ordinary middle and upper class drinkers -"moderate diners-out" and "virtuous dancing young ladies" -were drinking up to twice as much as his limit allowed (1870: 14). This was partly due to ignorance; anticipating our own problems with the contemporary unit (Boniface et al, 2013),…”