Reduced smoking: an introduction and review of the evidence.

The major questions about reductions in the number of cigarettes-day as a treatment goal are (1) how many smokers can reduce and maintain such reduction, (2) how much compensation will occur, (3) will reduced smoking significantly decrease the risk of smoking and (4) will reduction promote or undermine cessation. Naturalistic studies of smokers who are not trying to stop smoking indicate that a substantial minority of smokers spontaneously reduce their number of cigarettes-day and can maintain significant reductions (-7% to -43%) over long periods of time. Six experimental trials of smokers not interested in quitting were able to induce large reductions in cigarettes-day (-15% to -63%) using behavioral therapy and or nicotine replacement. Reductions in toxin exposure (carbon monoxide) were not as large but still substantial (-21% to -35%). The three studies with long-term follow-ups found little loss of effects over 6-30 months. Although face-valid, there is no direct test of whether reduced smoking will decrease smoking risks and such a study would need to be very large and last for a long time. None of the above-cited studies indicate that reduction undermines the probability of future cessation attempts and several found reduction promotes future cessation.