The Effect of Alcohol Strength on Alcohol Consumption: Findings from A Randomised Controlled Cross-Over Pilot Trial.

Abstract

Background Reducing the alcohol content of drinks has the potential to reduce population level alcohol consumption. This pilot study aimed to (1) test the feasibility of a randomised controlled trial (RCT) to assess the effect of alcohol strength on alcohol consumption within licensed premises in the United Kingdom (UK); and (2) provide data to estimate key parameters for a RCT. MethodsA double-blind randomised controlled cross-over pilot trial was based within four licensed premises in the UK. Participants (n=36) purchased and consumed ad libitum a 3.5% lager (intervention), and a taste matched 4.8% lager (control) during two separate study sessions. Descriptive statistics reported the efficacy and efficiency of the study processes, and the rates of licensed premises recruitment, and participant recruitment and attrition. Mean and the 95% confidence interval (CI) compared alcohol consumption between study conditions. The mean, standard deviation (SD) and CI of UK units of alcohol consumed were used to calculate a sample size for a RCT. Responses to participant questionnaires and duration of participation in study sessions between conditions were analysed.ResultsComponents of the study protocol were effective and efficient. The venue recruitment rate was less than anticipated whilst the participant recruitment rate was greater than anticipated. The rate of attrition was 23% and varied by less than 1% according to the arm of the trial. There was a reduction of alcohol consumed under the intervention conditions. Estimated mean difference, and 95% CI (UK units): -3.76 (-5.01 to -2.52). Based on a conservative estimate, using the smallest effect size in the CI (-2.52) and allowing for 23% attrition, the sample size required for a RCT powered at 95% is 53. Participants did not find one lager notably more pleasant in taste than the other: (on a scale of one to 10) -0.95 (-2.11 to 0.21). However, participants found the reduced-strength lager notably less enjoyable than the regular-strength lager: (on a scale of one to 10) -1.44 (-2.64 to -0.24) and they perceived themselves to be notably less intoxicated after consuming the reduced-strength lager: (on a scale of one to 10) -1.00 (-1.61 to -0.40).ConclusionA RCT is feasible with minor alterations to the study protocol and prior scoping work to establish different brands of alcohol that are more alike and more enjoyable than the intervention and control products used in the pilot trial. Trial registrationThe trial is registered in the American Economic Association (AEA) Randomised Controlled Trial (RCT) Registry as of 16 June 2017: https://www.socialscienceregistry.org/trials/2266. The unique identifying number is: AEARCTR-0002266.

Alcohol, calories, and obesity: A rapid systematic review and meta‐analysis of consumer knowledge, support, and behavioral effects of energy labeling on alcoholic drinks

“…A similar process could occur with alcoholic drink manufacturers, and reductions to energy content could be achieved through introducing new products 56 or reducing existing serving size and/or alcohol content by volume (ABV). As both reductions to alcoholic beverage serving sizes 57 and ABV 58 decrease alcohol consumption, industry reformulation as a result of energy labeling may be beneficial to public health.…”

Non‐alcoholic beer in the European Union and UK: Availability and apparent consumption

“…In a recently published overview of the literature on production, consumption and impact of low and no-alcohol drinks [5], we found very little research on this topic coming from a public health perspective (e.g. on labelling [6][7][8] and marketing [9]) and almost no research focusing on whether low-and no-alcohol products can contribute to reduction in overall ethanol consumption, although at least one innovative trial attempting to answer this question with reduced alcohol beer is currently in progress [10], and another small study found that reduction in wine alcohol content did not lead to increase of wine consumed [11]. Thus at this point, it is too early to make conclusions about this approach as a public health measure aimed at reducing alcohol-related harm.…”

Alcohol, calories and obesity: A rapid systematic review and meta-analysis of consumer knowledge, support and behavioural effects of energy labelling on alcoholic drinks

“…A similar process could occur with alcoholic drink manufacturers and reductions to energy content could be achieved through introducing new products 52 , or reducing existing serving size and/or alcohol content by volume (ABV). As both reductions to alcoholic beverage serving sizes 53 and ABV 54 decrease alcohol consumption, industry reformulation as a result of energy labelling may be beneficial to public health.…”