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Database of Abstracts of Reviews of Effects (DARE): Quality-assessed Reviews [Internet]. York (UK): Centre for Reviews and Dissemination (UK); 1995-.

Database of Abstracts of Reviews of Effects (DARE): Quality-assessed Reviews [Internet].

Nicotine patch therapy prior to quitting smoking: a meta-analysis

S Shiffman and SG Ferguson.

Review published: 2008.

CRD summary

This review compared the effectiveness of starting nicotine patch treatment prior to quitting smoking against starting patch treatment on the target quit day. The authors, and concluded that pre-quit nicotine patches roughly double the odds of quitting. Given the limited reporting of methods and lack of quality assessment of included studies, the conclusions should be interpreted with some caution.

Authors' objectives

To evaluate the incremental efficacy of starting nicotine patch treatment prior to quitting smoking, compared to starting patch treatment on the target quit day.

Searching

MEDLINE and Google Scholar were searched up to 24 February 2007 for relevant studies. Search terms were reported. In addition, prominent researchers in the field were contacted to identify additional published or unpublished studies.

Study selection

Studies were eligible for inclusion in the review if they recruited smokers interested in smoking cessation, treated participants with nicotine patches post-quit, included a pre-quit treatment phase in which participants were randomised to active nicotine patches or control (placebo patches or no patches) and reported biochemical verified abstinence rates four to six weeks after the target quit date.

Selected studies provided 15 mg or 21 mg pre-quit treatment with nicotine patches (PQNP) for two or four weeks. Co-interventions included mecamylamine 10 mg, low nicotine cigarettes and de-nicotinized cigarettes. Comparators included placebo patches and no patches. Primary continuous abstinence outcomes were measured at four or six weeks and secondary outcomes at 10 weeks or six months.

Assessment of study quality

The authors did not state that they assessed validity

Data extraction

The authors stated neither how data were extracted for the review nor how any reviewers performed the extraction.

Outcome data were extracted as odds ratios (ORs) with 95% confidence intervals (95% CIs).

Methods of synthesis

ORs were combined using a random-effects meta-analysis. Heterogeneity was assessed using the Q statistic and quantified using the I2 statistic. Subgroup analyses were conducted for those studies that did and did not use mecamylamine as a co-intervention. A sensitivity analysis was conducted in which the effect size was recalculated with each study excluded in turn.

Results of the review

Four RCTs (n=755) were included in the review. For all comparisons, outcomes were statistically homogeneous.

Six weeks continuous abstinence: PQNP appeared to increased abstinence both alone (two studies, OR 1.91 (95% CI: 1.16, 3.14), p=0.011) and in combination with mecamylamine (two studies, OR 2.07 (95% CI: 1.04, 4.10), p=0.037). Both subgroups combined gave an overall OR of 1.96 (95% CI: 1.31, 2.93), p=0.001.

Six months continuous abstinence: PQNP appeared to increased abstinence both alone (two studies, OR 2.20 (95% CI: 1.39, 3.48), p=0.001) and in combination with mecamylamine (two studies, OR 2.08 (95% CI: 0.96, 4.50), p=0.065).

Both subgroups combined gave an overall OR of 2.17 (95% CI: 1.46, 3.22), p<0.001.

Sensitivity analysis indicated that no single study was responsible for the observed differences.

Authors' conclusions

PQNP is an efficacious treatment strategy that roughly doubles the odds of quitting compared to the use of nicotine patches following quitting.

CRD commentary

The review question was clearly defined in terms of the participants, interventions, comparators, outcomes and study designs of interest. A search of one database was supplemented with internet searching and contacting experts. The range of search sources was limited and restrictions on language unclear, so it may be that relevant studies were missed. No attempt was made to systematically evaluate the quality of included studies, nor did it appear that attempts were made to minimise errors and bias in the selection or extraction of studies. The statistical methods used to synthesise the studies appeared broadly appropriate. Given the limited reporting of methods and the lack of quality assessment of included studies, the authors' conclusions should be interpreted with some caution.

Implications of the review for practice and research

Practice: The authors did not state any implications for practice.

Research: The authors stated that future research on the mechanism by which PQNP might improve smoking cessation outcomes was required and that further studies on the efficacy of the strategy were warranted.

Funding

The study was supported by GlaxoSmithKline Consumer Healthcare (GSKCH).

Bibliographic details

Shiffman S, Ferguson S G. Nicotine patch therapy prior to quitting smoking: a meta-analysis. Addiction 2008; 103(4): 557-563. [PubMed: 18339101]

Indexing Status

Subject indexing assigned by NLM

MeSH

Administration, Cutaneous; Humans; Nicotine /administration & dosage; Nicotinic Agonists /administration & dosage; Randomized Controlled Trials as Topic; Smoking Cessation /methods /psychology; Substance Withdrawal Syndrome /prevention & control /psychology

AccessionNumber

12008103416

Database entry date

13/05/2009

Record Status

This is a critical abstract of a systematic review that meets the criteria for inclusion on DARE. Each critical abstract contains a brief summary of the review methods, results and conclusions followed by a detailed critical assessment on the reliability of the review and the conclusions drawn.

CRD has determined that this article meets the DARE scientific quality criteria for a systematic review.

Copyright © 2014 University of York.

PMID: 18339101