Former smokers who find the smell of cigarette smoke pleasant are no more likely to start smoking again than those who don't.

The study followed 1,110 consecutive smokers who had achieved at least one week of validated abstinence from smoking. As part of routine follow-up, participants received a weekly questionnaire that included questions related to the pleasantness of the smell of others' smoke and the level of temptation resulting from the smell.

In the first week of abstinence, 23% of participants found the smell of other people's cigarette smoke at least slightly pleasant, 34% neutral and 43% unpleasant. However, 54% of the study group found the smell of smoke at least slightly tempting.

The authors found that patients who found the smell of smoke pleasant were no more likely to relapse than those who found it unpleasant.

However, those who found the smell tempting were more likely to relapse early on, although not in the later stages of the study. This was mirrored by the observation that temptation associated with the smell of smoke reduced over time.

Former smokers relapse after an attempt at quitting for a variety of reasons, including external stimuli such as watching someone else smoke.

Patients who have stopped smoking and who find the smell of smoke pleasant can be reassured that this does not increase their risk of relapse. Those who find the smell tempting can be reassured that this effect lessens quickly with time.

McRobbie H, Hajek P, Locker J. Does the reaction of abstaining smokers to the smell of other people's cigarettes predict relapse? Addiction 2008;103:1883-7