Commentary

The study by Carpenter et al goes some way towards answering a clinically relevant question of how to help patients who do not want to stop smoking. Clinicians often say something along the lines of “Well, if you can’t stop, see if you can at least cut down,” but are uncertain whether this will do more good than harm (if it has any effect at all).

This study examines whether advice on cutting down helps or hinders subsequent attempts to quit smoking. The results are reassuring. Those advised to cut down and then receive NRT made similar numbers of quit attempts to those offered motivational interviewing to encourage cessation. The motivational group had slightly higher abstinence rates at 6 months than those advised on reduction, and both groups had higher reported abstinence rates than a group who received telephone assessment but no advice about reducing or stopping smoking. Using NRT while continuing to smoke did not lead to unacceptable adverse effects.

Both the interventions and the data collection were conducted by telephone and no attempt was made at biochemical verification of self reported smoking status. As the authors point out, debate exists among researchers about how important it is to take such measurements. I think it unlikely that lack of verification affected the comparison between reduction and motivational interviewing, but it is possible that, relative to participants who received no intervention at all, there was inflation of self reported quit rates in the intervention arms. It therefore remains uncertain about how big an effect on quitting is achieved by reduction advice. This study is, however, reassuring that advising people who do not want to stop to try cutting down their smoking will not reduce their chances of making a quit attempt, and that advising them to use NRT to help cut down is unlikely to pose a serious health risk, even if they continue to smoke.