Our results suggest that NRT and combined smoking-reduction interventions increase long-term cessation among smokers who are not ready to quit smoking. Insufficient evidence is available regarding the efficacy of behavioral smoking-reduction interventions in promoting future abstinence among this group.
Although it is encouraging that NRT alone may promote abstinence in smokers not ready to quit, a major barrier to implementing such protocols is the long duration of therapy given to participants in these studies, ranging from 6 (Etter, et al., 2004
) to 18 months (Bolliger, et al., 2000
). This may be a costly treatment plan given that the majority of patients receiving it will not quit smoking. The Clinical Practice Guidelines recommend that nicotine gum should be used for up to 12 weeks, nicotine inhalers for up to 6 months, and nicotine patches for 8 weeks to achieve optimal treatment for tobacco users interested in cessation (Fiore, et al., May 2008
). Future studies should determine whether this treatment length is sufficient to produce a substantial treatment effect among smokers not ready to quit.
In the only study evaluating a behavioral smoking-reduction intervention (Glasgow, et al., 2009
), the results favored the behavioral intervention but did not achieve statistical significance. The study’s authors attributed this to two factors: increased tobacco-control strategies during the study and high drop-out rates in the intervention group. Participants in this study were scheduled for either outpatient surgeries or diagnostic procedures which may have had a significant effect on their motivation before and after the medical procedure and on study retention. Future studies should evaluate smoking-reduction behavioral interventions in a general population of smokers not ready to quit and explore ways to enhance retention.
The three studies examining combined intervention methods showed a significant effect of smoking reduction aided by NRT. However, two of these studies observed negative results (Carpenter MJ, 2003
; Joseph AM, 2008
), which may have been due to small sample sizes. The remaining study (Carpenter, et al., 2004
) observed a positive result. However, because the reduction intervention in this study consisted of two interventions (i.e., reduction counseling and the provision of free NRT), it is not clear whether the increase in quitting with NRT-assisted reduction is related to NRT availability, reduction itself, or both. Future studies should compare three groups: behavioral reduction intervention alone, NRT–assisted reduction with minimal behavioral support, and reduction intervention plus NRT to determine if behavioral counseling augments the effect of providing NRT.
An additional challenge in the literature is the lack of an operational definition of what constitutes a smoker who is “unwilling, unable, or not ready to quit smoking.” For the studies included in this review, the time frame for intention-to-quit varied from “not ready to quit in the next 6 months” to “not ready to quit immediately.” One possible approach would be to use the stages-of-change definitions of pre-contemplators and contemplators as a common definition for smokers who are “unwilling to quit” (Prochaska, Velicer, DiClemente, & Fava, 1988
). A sample of contemplators may be more amenable to a rate-reduction intervention than pre-contemplators are. Another challenge is that most rate-reduction studies report only point-prevalence smoking abstinence. Future studies should follow the published recommendations for measuring abstinence (Hughes, et al., 2003
) in trials of smokers not currently trying to quit by tying follow-up to the start of the intervention. An appropriate report would consist of prolonged abstinence as the primary outcome measure and point-prevalence abstinence as a secondary measure at 6-month follow-up.
In conclusion, pharmacological and combined smoking-reduction interventions double the odds of long-term smoking abstinence. Additional research is needed to further refine the behavioral interventions and the duration of pharmacotherapy that are most effective for smoking reduction.