Evaluating possible intended and unintended consequences of the implementation of alcohol minimum unit pricing (MUP) in Scotland: a natural experiment protocol

Intended and unintended consequences of the implementation of minimum unit pricing of alcohol in Scotland: a natural experiment

Background

Scotland was the first country to implement minimum unit pricing for alcohol nationally. Minimum unit pricing aims to reduce alcohol-related harms and to narrow health inequalities. Minimum unit pricing sets a minimum retail price based on alcohol content, targeting products preferentially consumed by high-risk drinkers. This study comprised three components.

Objectives

This study comprised three components assessing alcohol consumption and alcohol-related attendances in emergency departments, investigating potential unintended effects of minimum unit pricing on alcohol source and drug use, and exploring changes in public attitudes, experiences and norms towards minimum unit pricing and alcohol use.

Design

We conducted a natural experiment study using repeated cross-sectional surveys comparing Scotland (intervention) and North England (control) areas. This involved comparing changes in Scotland following the introduction of minimum unit pricing with changes seen in the north of England over the same period. Difference-in-difference analyses compared intervention and control areas. Focus groups with young people and heavy drinkers, and interviews with professional stakeholders before and after minimum unit pricing implementation in Scotland allowed exploration of attitudes, experiences and behaviours, stakeholder perceptions and potential mechanisms of effect.

Setting

Four emergency departments in Scotland and North England (component 1), six sexual health clinics in Scotland and North England (component 2), and focus groups and interviews in Scotland (component 3).

Participants

Research nurses interviewed 23,455 adults in emergency departments, and 15,218 participants self-completed questionnaires in sexual health clinics. We interviewed 30 stakeholders and 105 individuals participated in focus groups.

Intervention

Minimum unit pricing sets a minimum retail price based on alcohol content, targeting products preferentially consumed by high-risk drinkers.

Results

The odds ratio for an alcohol-related emergency department attendance following minimum unit pricing was 1.14 (95% confidence interval 0.90 to 1.44; p = 0.272). In absolute terms, we estimated that minimum unit pricing was associated with 258 more alcohol-related emergency department visits (95% confidence interval –191 to 707) across Scotland than would have been the case had minimum unit pricing not been implemented. The odds ratio for illicit drug consumption following minimum unit pricing was 1.04 (95% confidence interval 0.88 to 1.24; p = 0.612). Concerns about harms, including crime and the use of other sources of alcohol, were generally not realised. Stakeholders and the public generally did not perceive price increases or changed consumption. A lack of understanding of the policy may have caused concerns about harms to dependent drinkers among participants from more deprived areas.

Limitations

The short interval between policy announcement and implementation left limited time for pre-intervention data collection.

Conclusions

Within the emergency departments, there was no evidence of a beneficial impact of minimum unit pricing. Implementation appeared to have been successful and there was no evidence of substitution from alcohol consumption to other drugs. Drinkers and stakeholders largely reported not noticing any change in price or consumption. The lack of effect observed in these settings in the short term, and the problem-free implementation, suggests that the price per unit set (£0.50) was acceptable, but may be too low. Our evaluation, which itself contains multiple components, is part of a wider programme co-ordinated by Public Health Scotland and the results should be understood in this wider context.

Future work

Repeated evaluation of similar policies in different contexts with varying prices would enable a fuller picture of the relationship between price and impacts.

Trial registration

Current Controlled Trials ISRCTN16039407.

Funding

This project was funded by the National Institute for Health Research (NIHR) Public Health Research programme and will be published in full in Public Health Research; Vol. 9, No. 11. See the NIHR Journals Library website for further project information.

What on-line searches tell us about public interest and potential impact on behaviour in response to minimum unit pricing of alcohol in Scotland

AIMS

To investigate whether the introduction of minimum unit pricing (MUP) in Scotland on 1 May 2018 was reflected in changes in the likelihood of alcohol-related queries submitted to an internet search engine, and in particular whether there was any evidence of increased interest in purchasing of alcohol from outside Scotland.

DESIGN

Observational study in which individual queries to the internet Bing search engine for 2018 in Scotland and England were captured and analysed. Fluctuations over time in the likelihood of specific topic searches were examined. The patterns seen in Scotland were contrasted with those in England.

SETTING

Scotland and England.

PARTICIPANTS

People who used the Bing search engine during 2018.

MEASUREMENTS

Numbers of daily queries submitted to Bing in 2018 on eight alcohol-related topics expressed as a proportion of queries on that day on any topic. These daily likelihoods were smoothed using a 14-day moving average for Scotland and England separately.

FINDINGS

There were substantial peaks in queries about MUP itself, cheap sources of alcohol and online alcohol outlets at the time of introduction of MUP in May 2018 in Scotland, but not England. These were relatively short-lived. Queries related to intoxication and alcohol problems did not show a MUP peak, but were appreciably higher in Scotland than in England throughout 2018.

CONCLUSIONS

Analysis of internet search engine queries appears to show that a fraction of people in Scotland may have considered circumventing minimum unit pricing in 2018 by looking for on-line alcohol retailers. The overall higher levels of queries related to alcohol problems in Scotland compared with England mirrors the corresponding differences in alcohol consumption and harms between the countries.

Impact of minimum unit pricing on alcohol purchases in Scotland and Wales: controlled interrupted time series analyses

BACKGROUND

As a policy option to reduce consumption of alcohol and the harm it does, on May 1, 2018, Scotland introduced a minimum price of 50 British pence (p) per unit of alcohol (8 g) sold; Wales followed suit on March 2, 2020, with the same minimum unit price (MUP). We analysed household purchase data based on bar codes to assess the impact of these policy options in the medium term for Scotland and in the immediate term for Wales.

METHODS

For these location-controlled, interrupted time series regression analyses, the data source was Kantar WorldPanel's household shopping panel, which, at the time of our analysis, included 35 242 British households providing detailed information on 1·24 million separate alcohol purchases in 2015-18 and the first half of 2020. With no data exclusions, we analysed the impact of introducing MUP in Scotland, using purchases in northern England as control, and in Wales, using western England as control. The studied changes associated with MUP were price paid per gram of alcohol purchased, grams of alcohol purchased, and amount of money spent on alcohol.

FINDINGS

In Scotland, price increases and purchase decreases following the introduction of MUP in 2018 were maintained during the first half of 2020. The difference between Scotland and northern England in 2020 was a price increase of 0·741 p per gram (95% CI 0·724-0·759), a 7·6% increase, and a purchase decrease of 7·063 g per adult per household per day that an alcohol purchase was made (6·656-7·470), a 7·7% decrease. In Wales, the introduction of MUP led to similar results. The difference between Wales and western England was a price increase 0·841 of 0·841 p per gram (0·732-0·951), an 8·2% increase, and a purchase decrease of 7·052 g per adult per household per day that an alcohol purchase was made (6·463-7·640), an 8·6% decrease. For both Scotland and Wales, reductions in overall purchases of alcohol were largely restricted to households that bought the most alcohol. The introduction of MUP was not associated with an increased expenditure on alcohol by households that generally bought small amounts of alcohol and, in particular, those with low incomes. The changes were not affected by the introduction of COVID-19 confinement in the UK on March 26, 2020.

INTERPRETATION

The evidence base supporting the positive, targeted impact of MUP is strengthened by the comparable results for Scotland and Wales. The short-term impact of MUP in Scotland during 2018 is maintained during the first half of 2020. MUP is an effective alcohol policy option to reduce off-trade purchases of alcohol and should be widely considered.

FUNDING

None.

The behaviour of alcohol-dependent drinkers of spirits during level 4 COVID-19 lockdown in Auckland, New Zealand

Introduction

Behaviour of alcohol drinkers during previous major public health or economic crises has varied, with reductions in use generally occurring during periods of reduced availability. This study aimed to discover the behaviour of a group of dependent drinkers of spirits during a 33‐day period of complete closure of physical stores selling spirits during COVID‐19 lockdown in Auckland, New Zealand, March 2020.

Methods

Electronic clinical records of drinkers waitlisted to complete an alcohol detox at the in‐patient service were followed from day 1 of lockdown and outcomes at the end of the period analysed.

Results

Drinkers of spirits were statistically more successful in stopping drinking (P = 0.002) than those of wine or beer. Only 26% chose to switch to an alternate alcohol type initially.

Discussion and Conclusion

A sudden reduction in availability of spirits resulted in positive behaviour change in spirits drinkers compared to those of other alcohol types, aided by the support of detox services. Internet alcohol purchasing, while not used by this group, deserves close future scrutiny due to its potential to increase alcohol availability in dependent drinkers.

Evaluation of Minimum Unit Pricing of Alcohol: A Mixed Method Natural Experiment in Scotland

In May 2018, Scotland became the first country in the world to implement minimum unit pricing (MUP) for all alcoholic drinks sold in licensed premises in Scotland. The use of a Sunset Clause in the MUP legislation was a factor in successfully resisting legal challenges by indicating that the final decision on a novel policy would depend on its impact. An overarching evaluation has been designed and the results will provide important evidence to inform the parliamentary vote on the future of MUP in Scotland. The evaluation uses a mixed methods portfolio of in-house, commissioned, and separately funded studies to assess the impact of MUP across multiple intended and unintended outcomes related to compliance, the alcoholic drinks industry, consumption, and health and social harms. Quantitative studies to measure impact use a suitable control where feasible. Qualitative studies assess impact and provide an understanding of the lived experience and mechanism of change for key sub-groups. As well as providing important evidence to inform the parliamentary vote, adding to the international evidence on impact and experience of alcohol pricing policy across a broad range of outcomes, this approach to evaluating novel policy interventions may provide guidance for future policy innovations.