Response from Sir Robert Chote to Sandesh Gulhane MSP – minimum unit pricing

Dear Dr Gulhane,

Thank you for your letter of 3 July regarding publications about the impact of minimum unit pricing (MUP) for alcohol in Scotland.

You raised concerns about the communication of Public Health Scotland’s (PHS) evaluation of the MUP policy, which concluded in a final report published in June (that synthesized evidence from a number of studies). You also raised concerns about a Scottish Government press release welcoming that report and an earlier health impact study published in March by authors from PHS, the University of Glasgow and the University of Queensland. We have also looked at an ‘at a glance’ document produced by PHS.

Our remit covers the production and use of official statistics and does not extend to research or policy evaluation. As such, we have not conducted a full investigation of the content or methodology of the PHS reports. Instead, we have focused on how statistical evidence has been communicated and we consider that the findings in the final PHS report are communicated clearly and impartially.

Communication of the PHS evaluation report (published June 2023)

The original version of the Scottish Government press release stated that:

“In their final report of a series, researchers said that ‘robust, independent evaluation’ and the best available, wide-ranging evidence drawing on 40 independent research publications, showed that the MUP has been effective in its main goal of reducing alcohol harm with the reduction in deaths and hospital admissions specific to the timing of MUP implementation”.

This wording might suggest to many readers that most or all of the studies referred to examined the health impact of MUP. But the evaluation report explains that of the 40 papers included, only eight provided evidence on alcohol-related health outcomes. The remaining 32 examined other potential effects of the policy such as on alcohol consumption, social outcomes, compliance by retailers and product prices. Of the eight papers which studied health outcomes, one looked at deaths and hospitalisations and found a beneficial quantitative impact on these outcomes. Based on the other seven papers, the report concluded that there was “no consistent evidence that MUP impacted on other alcohol-related health outcomes such as ambulance callouts, emergency department attendances and prescribing of medication for alcohol dependence”.

Communication of the PHS/Glasgow/Queensland study (published March 2023)

The Scottish Government press release and the PHS ‘at a glance’ document both referred to the results of the PHS/Glasgow/Queensland study. However, information about the level of uncertainty associated with the reduction in hospitalisations and deaths was not included in either output, despite being emphasised in the study. For example, the figures are estimates based on statistical modelling and the reduction in hospital admissions was not found to be statistically significant.

Summarising technical data, especially for a public audience, is challenging. Press releases, factsheets, tweets and other communications require condensed information, but it still serves users best to include caveats about the uncertainty or limitations of statistical evidence. In this case, caveats did not carry through from the final PHS report to the press release and ‘at a glance’ document.

The Office for Statistics Regulation has discussed these issues, and its broader guidance on communicating uncertainty, with PHS and the Scottish Government. It is good to see that, as a result, PHS has updated its at-a-glance summary and the Scottish Government has updated its press release to ensure that the uncertainty around the estimates is more clearly communicated. I am also pleased to report that both have committed to improving the communication of uncertainty in future outputs.


Yours sincerely,

Sir Robert Chote


Related links

Letter from Sandesh Gulhane MSP to Sir Robert Chote – minimum unit pricing

Letter from Sandesh Gulhane MSP to Sir Robert Chote – minimum unit pricing

Dear Sir Robert,

I am writing to request a review of the Public Health Scotland report ‘Evaluating the impact of minimum unit pricing for alcohol in Scotland: A synthesis of the evidence’ and the associated publicity and ministerial statements.

It purports to be “the final report from the PHS evaluation of minimum unit pricing for alcohol in Scotland”.

It is likely to be used in Scottish Government decision making on whether to continue with MUP and whether to raise the minimum unit price of alcohol.

However, I am concerned the report and associated publicity and ministerial statements significantly overstate the health impact of MUP, and under-represent the significant uncertainty in the wider body of research and among the scientific community.

I will outline my concerns in turn.

The press release

On 27 June 2023 the Scottish Government distributed the following press release.

It states the conclusion that MUP “has saved lives, reduced hospital admissions and had a positive impact on health” was drawn from “robust, independent evaluation’ and the best-available, wide-ranging evidence drawing on 40 independent research publications”.

It also states: “This follows a study published in March by PHS and University of Glasgow showing MUP reduced alcohol consumption by 3%, deaths directly caused by alcohol consumption by 13.4% and hospital admissions by 4.1%. compared to what would have happened if MUP had not been in place.”

However, this conclusion is not drawn from 40 publications. 32 of these publications referenced in the “final report” are silent on health impacts and focus on other issues such as consumption.

Of the eight publications that do address health impacts, seven of them are inconclusive.

Only one study concluded MUP had reduced deaths — the PHS and University of Glasgow study mentioned in the press release.

This study was led by Grant MA Wyper, public health adviser to PHS.

This “final report” does not “follow the PHS and University of Glasgow study”. It merely restates its findings.

Furthermore, it was not “independent”. It was commissioned by PHS and led by a PHS adviser.

The PHS/Glasgow University report was itself a retread of a report that appeared in The Lancet the previous day.

These reports are presented as two distinct studies in the latest PHS “final report” as Wyper et at (2023a) and Wyper et al (2023b).

This “final report” does not build on the Wyper study. The seven other studies addressing health impacts are inconclusive.

The conclusion that MUP has reduced deaths was not robust, nor drawn from wide-ranging independent evidence. It was drawn from a single PHS report.

Also, the report itself states that the 4.1 per cent reduction in hospitalisations was not statistically significant.

Therefore, the Scottish Government cannot definitively say “MUP reduced…hospital admissions by 4.1%”.

The Lancet study

The assertion that there were 13.4% fewer deaths “compared with what would have been observed in the absence of MUP legislation” overstates the uncertainty in statistical modelling.

No statistical model can say definitively what “would have” happened, as The Lancet study acknowledges in its methodology.

Indeed, “would have” becomes “might have” in the discussion section of the study.

“Study outcomes were assessed using a controlled interrupted time series study design, allowing us to determine the difference between outcomes we observed and our best representation of what might have happened under the counterfactual situation that MUP legislation was not enacted in Scotland.”

It concludes deaths rose faster in England in the absence of MUP therefore MUP “averted…an average of 156 deaths” each year in Scotland.

An additional 156 deaths a year would be a significant acceleration of the trend seen in the preceding 20 years, which was generally downward in the first decade and plateaued in the low thousands before the pandemic.

An acceleration this size was not witnessed in any of the regions of England with a similar population and demographic to Scotland, for example North West England, which saw a post-pandemic increase of a similar magnitude to Scotland despite the cheaper alcohol.

Criticisms of the Lancet study

Dr Adam Jacobs, Senior Director, Biostatistical Sciences at Premier Research, challenged the methodology behind the 13.4 per cent increase.

He said: “It is plausible that the MUP policy would bring down deaths and hospitalisations due to alcohol consumption, but I don’t think this paper shows it convincingly.”

Prof Kevin McConway, Emeritus Professor of Applied Statistics, The Open University, rightly took issue with the “causal interpretation” in The Lancet study.

He said: “This is an observational study, and no matter how well other factors are controlled for, it can never prove conclusively that the changes observed in deaths were due to the minimum unit pricing policy. In my view there hasn’t been enough caution given around assuming this relationship is causal…”

“We can’t say that MUP definitely led to a 13.4% reduction in deaths, though that does clearly remain an important possibility…”

“While it’s possible that the deaths or hospitalisations would have decreased enough to be detectable in the follow-up period here of 32 months after MUP, it’s also possible…that they aren’t clearly detectable on that time scale, though (if they really exist) the effect should show up, and indeed be much larger, later. And given what the time lag specifications look like in the Holmes paper, in another 7 or 8 years the reductions in deaths would be immense, implausibly immense indeed, given the size of the estimate after just over 2.5 years.

“Or it’s possible that what is being picked up in the new study is an effect of a change in alcohol consumption that occurred considerably earlier than MUP, so couldn’t have been caused directly by MUP…”

“So overall, in my view, there remains some doubt about whether MUP definitely caused the alcohol consumption change and therefore whether it is responsible for reductions in deaths.”

The “final report” at a glance

The at a glance conclusion states:

“Overall, the evidence supports that MUP has had a positive impact on health outcomes, including alcohol-related health inequalities.”

However, the finding for health above states:

“MUP reduced deaths directly caused by alcohol consumption by 13.4% and hospital admissions by 4.1%.

“Reductions were greatest for men and those living in the most deprived areas of Scotland.

“There is no consistent evidence of impact, positive or negative, on other health outcomes.”

This is not “overall” evidence. It’s a single study.

The conclusion should have stated:

“One study supports that MUP has had a positive impact on deaths and there is no consistent evidence of impact, positive or negative, on other health outcomes.”

The “final report” briefing

The briefing concludes:

“Taken together, the evidence supports that MUP has had a positive impact on health outcomes.”

Taken together, the evidence does not support this. A single questionable study estimated the reductions of deaths. The rest of the evidence was inconclusive.

The “final report”

Section 3.3 on page 33 confirms evidence relating to alcohol-related health outcomes was drawn from eight papers, not the 40 papers that the press release suggests.

It confirms the 13.4 per cent death reduction figure was drawn solely from the Wyper paper (Item 25 in the bibliography) and confirms the 4.1 per cent reduction in hospitalisations in Wyper was “non-significant”.

It cites Wyper at length but gives short shrift to the other inconclusive papers.

It states:

“The five other papers that contributed relevant quantitative evidence found no evidence of impacts in alcohol-related health outcomes, either positive or negative: there appears to have been no effect at a population level on alcohol-related ambulance callouts, (Manca 2022) prescriptions for treatment of alcohol dependence (Manca 2023) emergency department attendance (So 2021) or the level of alcohol dependence or self-reported health status in drinkers recruited through alcohol treatment services in Scotland, relative to England. (Holmes 2022).”

Ministerial statements

On June 27, Humza Yousaf, Scotland’s first minister tweeted:

“When @ScotGov proposed Minimum Unit Pricing over a decade ago, it was a pioneering approach to tackling alcohol harm and some had their doubts.

“Increasing evidence is now vindicating our approach. It’s saving over 150 lives a year.”

Analysis: There is no increasing evidence. There is one consistently rehashed and questionable PHS paper and about half a dozen inconclusive papers.

On June 27, The SNP tweeted MUP has led to “a major reduction in alcohol related deaths”

Analysis: Alcohol related deaths have risen since MUP was imposed. The SNP omitted the crucial caveat that the reduction was based on a hypothetical model.

Please investigate the matters raised in this correspondence and advise.


Yours faithfully,

Dr Sandesh Gulhane
MSP, Glasgow Region
Shadow Cabinet Secretary for Health and Social Care
Scottish Conservative and Unionist Party


Related links

Response from Sir Robert Chote to Sandesh Gulhane MSP – minimum unit pricing

Jackie Baillie MSP to Sir David Norgrove: Test and Protect Statistics

Dear Sir David,

Misleading statistics used by the Scottish Government for Test and Protect

I write to you regarding the above matter.

Following media reports this weekend, I am deeply concerned to learn that the Scottish Government has been publishing Test and Protect figures that significantly overestimate its performance in meeting the World Health Organisation’s (WHO) target, which states that “at least 80% of new cases” should “have their close contacts traced and in quarantine within 72 hours of case confirmation.”

The figures that have been published to date are misleading as they do not include “failed” cases. When the 72-hour success rate calculation is done with the failed cases added in, the 80% WHO target has actually been missed by Test and Protect over the period since records began (week ending Aug 9, 2020, to week ending September 12, 2021).

The correct use of statistics is vital, particularly when we are encouraging everyone to take regular tests to stop the spread of the virus. It is imperative that the public have faith in the accuracy and truthfulness of the data that is published by the Scottish Government. As such, I would be grateful if you could investigate this matter and take appropriate action as you see fit.

Yours sincerely,

Jackie Baillie MSP


Related links:

Response from Sir David Norgrove to Jackie Baillie MSP: Test and Protect Statistics

Ed Humpherson to Scott Heald: Test and Protect statistics


Response from Sir David Norgrove to Jackie Baillie MSP: Test and Protect Statistics


Dear Ms Baillie,


Thank you for your letter of 27 September regarding your concerns over the use of Test and Protect statistics by Scottish Government.

Scottish Government should be clearer about the limitations in comparing figures for Scotland (published by Public Health Scotland) with the World Health Organization target for contact tracing.

Ed Humpherson, Director General for Regulation, has today written to Public Health Scotland, copied to the Chief Statistician in Scottish Government, welcoming improvements to the presentation of these statistics. I enclose a copy of his letter.


Yours sincerely,
Sir David Norgrove


Related links:

Ed Humpherson to Scott Heald: Test and Protect statistics

Jackie Baillie MSP to Sir David Norgrove: Test and Protect Statistics