Tuesday 19 December 2023

First sign of failure for minimum pricing in Ireland

A study evaluating minimum unit pricing (MUP) in Ireland has been published (the first, I think). It found a statistically significant increase in wholly alcohol-related presentations at an emergency department (ED) of a Dublin hospital, but you'd never guess it from the abstract.

Findings

Alcohol consumption was a factor in 19.4% of ED presentations and in 17.3% of hospital admissions across the entire study period. A reduction in overall alcohol-related ED presentations was noted in the period following MUP, although it is not possible to conclude a direct effect.

Conclusion

Alcohol-related harm places a significant strain on EDs and hospitals, and the impact of MUP on hospital burden in Ireland merits further evaluation. Effective measures at local and population levels are urgently required to address this burden.

 
MUP was introduced on 4 January 2022. The minimum price in Ireland is €1.00 per 10 g of alcohol, substantially more than the 50p per 8 g of alcohol in Scotland and Wales (Irish units are larger). 
 
The authors looked at data from the hospital in two weeks preceding the introduction of MUP (November and December 2021) and compared it with two weeks in March and April 2022. One of the researchers was in the hospital throughout and interviewed anyone who was there with an ailment that is deemed partially or wholly attributable to alcohol, asking them what they liked to drink and administering the Alcohol Use Disorders Identification Test (AUDIT) to see if they were dependent drinkers. 73% agreed to be interviewed.
 
The researchers found that presentations that were wholly attributable to alcohol trebled after MUP was introduced. This is not immediately obvious from the way they present the data because they prefer to look at percentages of alcohol-related presentations rather than the number of presentations, but as you can see below the number of 'acute wolly [sic!] related' presentations rose from 5 to 15 and the proportion of alcohol-related presentations that were wholly related to alcohol rose by 19.8 percentage points. Normally, this would be presented as a 200% increase.
 

 
This is obviously not what they were hoping for and so they left it out of the abstract, although they do not acknowledge it in the text:
 
In Period 1, there were 5 cases of alcohol intoxication, and in Period 2, there were 14 cases of alcohol intoxication and 1 case of alcohol withdrawal.
... Although there was a reduction in overall alcohol-related presentations, we observed a significant increase in acute wholly related presentations, and this subgroup represented individuals with alcohol dependence (Supplementary Table S7). The reason for an increase in acute wholly related presentations such as alcohol intoxication or poisoning during Period 2 is unclear, but it could be related to factors noted in the Scottish evaluation of MUP in which the introduction of MUP was associated with reduced household expenditure on food with increased availability of funds for alcohol or switching to consuming more spirits amongst persons with alcohol dependence.
 
Quite possibly. These are the kinds of thing sensible people warned about in advance, but they were ignored.
 
Still, at least they've got their reduction in alcohol-related presentations overall. So why are they so circumspect in the abstract, saying 'it is not possible to conclude a direct effect'?

I suspect it is because most of the partially attributable presentations were very unlikely to have been affected by minimum pricing, even in theory. A large chunk of them (4 out of 10) were not just 'partially related' but 'chronic'. Most chronic diseases are unlikely to be affected in such a short space of time by any public health intervention. And, as with the obesity data I discussed yesterday, these people were not necessarily in the ED because of drinking. Some of them probably didn't even drink. These are all simply diseases that can be caused by excessive alcohol consumption.
 
 
The same is true of the acute partially related presentations which mostly involve accidents. There were a lot of these both before and after MUP (it was an accident and emergency department, after all) but there were fewer after. Again, we don't know how many of these people had been drinking or whether they drank at all (the researchers do because they did on AUDIT test on most of them, but they don't tell us - interested readers may find something to explore in the Supplementary Table S7). They are just injuries that can be affected by alcohol. Presumably there are other factors, such as the weather. Maybe there are simply more people drinking in December than in March (the authors admit that their study "did not address potential seasonality of alcohol presentations").


The authors don't conclude that the minimum price should be higher, but prepare yourself for them to start saying that if a few more studies show that the policy has been a flop, as in Scotland. This is quite a small study and the statistical analysis is eccentric to say the least, but it's a nice example of 'public health' researchers burying the lede. If the aim of the policy had been to increase alcohol-related harm, they would have made it very clear that emergency department presentations that are directly caused by alcohol have risen 200% under minimum pricing - and you would have seen this study reported on the BBC. 


No comments: