On Thursday 23rd May #PHTwitJC discussed the following paper:
A C Wagenaar et al (2009) Effects of beverage alcohol price and tax levels on drinking: a meta-analysis of 1003 estimates from 112 studies, Addiction, 104, 179–190 PDF
The full transcripts can be found on our archive page, however I’ve tried to summarise some of the key debates below.
1 – Were the aims of this study clear?
Although we all understood what that authors were hoping to achieve in this study, it was noted that the aims were not explicitely stated by the authors. An important observation was made by @DotBirch:
@rebeccahams noted that the target population was not clearly defined. Also, some commented that the outcomes were complex and not clearly defined (e.g. the authors did not explain how they were measuring drinking behaviour). For example @rebeccahams tweeted:
2 – Was the systematic review comprehensive?
It was noted that the authors had not followed PRISMA guidelines for reporting methods of systematic reviews. For example @dotbirch tweeted:
Overall we agreed that the review was comprehensive from what was written, but noted that the presentation of such information could’ve been improved through abiding to the PRISMA guidelines.
3 – Were any adjustments made for study size or quality?
This wasn’t very clear. There was no information on data extraction nor quality assessment, and although some information was provided it was laid out in the narrative text rather than in tables or graphs.
As @DotBirch noted, adjustment for study size was done:
4 – Do you believe the results? Could anything else explain these findings?
The results of the paper show a strong statistically significant association, and can be summarised as follows:
Some further information would be useful to be able to more fully interpret these results. Suggestions included controlling for potential confounders such as: general living costs, GDP, sub-group analysis… and looking at potential bias, e.g. definition and measures of ‘drinking behaviour’.
5 – What implications do the findings have for public health practice & policy?
The results of the paper suggest a strong association between alcohol pricing and drinking behaviour, which adds to the evidence that a population-level intervention for minimising alcohol misuse. @DotBirch suggested:
…to which @matandbec agreed:
Following the lively discussion and debate we reflected upon the importance of communicating key messages from research, as well as being transparant in the methods used to derive at those messages. As @PHTwitJC tweeted: