School programmes aimed at preventing smoking work, a major new review indicates.

According to UK scientists, smoking currently causes around five million preventable deaths every year and this figure is expected to increase in the coming years. Prevention programmes in schools attempt to tackle this issue early, either by preventing young people from taking up the habit or catching people before the habit has become too difficult to break.

The scientists from the University of Oxford set out to see whether these programmes actually work. They analysed data from over 130 studies carried out in 25 countries and involving more than 425,000 children aged between five and 18.

The analysis revealed that within the first year of such a programme, there was no significant effect on levels of smoking. However, in studies that included a longer follow-up, there were far fewer smokers in the groups targeted by smoking prevention programmes than in control groups.

Some of the methods used in the programmes included the development of social skills and teaching students how to resist the social pressure to smoke. Programmes that used a combination of these approaches seemed to be particularly successful.

Programmes that used, for example, information only were not as successful.

The scientists noted that ‘booster sessions', designed to reinforce the effects of the original programme, did not appear to make any difference to the number of young people who went on to be smokers.

"This review is important because there are no other comprehensive reviews of world literature on school-based smoking prevention programmes. However, over half were from the US, so we need to see studies across all areas of the world, as well as further studies analysing the effects of interventions by gender," the Oxford team said.

Details of these findings are published in the Cochrane Database of Systematic Reviews 2013.