Plain packaging of cigarettes may reduce the number of people who smoke, according to a new review of the evidence.
The Cochrane Review analysed 51 studies of standardised packaging, involving about 800,000 participants, which each analysed different factors such as how packs may affect overall smoking levels, quit attempts, number of cigarettes smoked and appeal of cigarette packs.
The review comes after Australia became the first country to implement standardised plain tobacco packaging in 2012. France adopted plain packaging laws earlier this year, the UK is set to introduce standardised packaging this month, and several other countries are intending to implement new cigarette packaging rules, the review authors said.
Standardised packaging generally involves the use of the same uniform colour on all tobacco packs, with no brand imagery and the brand name written in a specified font, colour and size, they said.
What the plain packaging studies showed
Only five of the 51 studies in the review provided data on the key outcome of changes in tobacco use prevalence.
One Australian study looking at data from 700,000 people found a half a percentage point drop in the proportion of people who used tobacco following the introduction of plain packaging.
Four studies looked at whether current smokers changed the number of cigarettes they smoked after the new packaging was implemented, with mixed results.
Two further studies looked at whether quit attempts had increased after plain packaging was introduced with one study finding quit attempts increased from 20.2% prior to the introduction of plain packaging to 26.6% one year after the change. The other study found a 78% increase in the number of calls to quitlines after the introduction of plain packaging.
The researchers said the most consistent evidence showed that people found plain cigarette packs less appealing than branded packs.
Because only Australia had introduced plain packaging laws at the time of the analysis, they said their conclusions could not be completely certain.
However, the review concluded that standardised packaging may decrease tobacco use, and that there was no evidence to suggest it increased tobacco use.