Smokers who try to cut down the amount they smoke before stopping are less likely to quit than those who choose to quit all in one go, Oxford University researchers have found. Their study is published in journal Annals of Internal Medicine.

Most experts say that people should give up in one go, but most people who smoke seem to try to stop by gradually reducing the amount they smoke before stopping. This research helps to answer the questions 'Which approach is better?', and 'Are both as likely to help people quit in the short and long term?'.

Dr Nicola Lindson-Hawley led the research. She explained: 'We recruited 697 smokers who had chosen to stop smoking. They were split into two groups. One group -- the 'abrupt cessation' group -- set a quit day and stopped all smoking on that day. The second group -- the 'gradual cessation' group -- set a quit day but gradually reduced their tobacco use in the two weeks leading up to that date.

'Both groups had advice and support and access to nicotine patches and nicotine replacement therapy, like nicotine gum or mouth spray.'

Once quit day had passed, volunteers were assessed weekly for the next four weeks, and after six months. As well as asking them about how they were doing, the researchers measured the amount of carbon monoxide they were breathing out -- an objective way to check whether people were actually sticking to their quit plan.

At four weeks, 39% of the gradual cessation group had kept off tobacco, compared to 49% of the abrupt cessation group, meaning that the abrupt group were 25% more likely to quit. The difference between the groups began on quit day, when more of the abrupt group attempted to quit (defined as having at least 24 hours with no tobacco), compared to the gradual cessation group.

Dr Lindson-Hawley said: 'The difference in quit attempts seemed to arise because people struggled to cut down. It provided them with an extra thing to do, which may have put them off quitting altogether. If people actually made a quit attempt then the success rate was equal across groups. We also found that more people preferred the idea of quitting gradually than abruptly; however regardless of what they thought they were still more likely to quit in the abrupt group.

'It is important to note that these results were found in people who wanted to quit soon and who were receiving counselling support and using nicotine replacement therapy. For these people the best advice appears to be to pick a day and stop smoking completely on that day. However, as we found that at the start of the study many people cannot imagine being able to stop completely. For these people it is much better to attempt to cut down their smoking than do nothing at all and we should increase support for gradual cessation to increase their chances of succeeding.'