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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].

Smoking cessation interventions in COPD: a network meta-analysis of randomised trials

R Strassmann, B Bausch, A Spaar, J Kleijnen, O Braendli, and MA Puhan.

Review published: 2009.

Link to full article: [Journal publisher]

CRD summary

This well-conducted review concluded that a small body of evidence suggested that smoking cessation counselling combined with nicotine replacement therapy was more effective than other treatments in patients with chronic obstructive pulmonary disease, but that substantially more research is needed. These conclusions are likely to be reliable.

Authors' objectives

To rank order the effectiveness of smoking cessation interventions for patients with chronic obstructive pulmonary disease.

Searching

MEDLINE, EMBASE, LILACS (Latin American and Caribbean Health Sciences Literature), Cochrane Database of Systematic Reviews, Cochrane Central Register of Controlled Trials (CENTRAL), DARE, HTA database, CINAHL, BIOSIS Previews and the National Research Register were searched from inception to November 2008. Search terms were reported. References of retrieved studies and existing reviews were screened and the related article function in PubMed was used to identify additional studies. No language restrictions were applied.

Study selection

Randomised controlled trials (RCTs) that assessed smoking cessation interventions in patients with spirometrically confirmed chronic obstructive pulmonary disease and/or physician-diagnosed chronic obstructive pulmonary disease were eligible for inclusion. Any non-pharmacological or pharmacological intervention that assisted patients in preparing a quit-smoking attempt and that supported patients during smoking abstinence were eligible.

The primary review outcome measure was prolonged abstinence rate at six months or more, with biochemical confirmation. In the absence of data on prolonged abstinence, data on smoking point prevalence were used. Mortality was also assessed.

Included patients had mild-to-moderate or moderate-to-severe airflow obstruction, with mean age ranging from 44 to 66 years. Specific interventions in included trials consisted of smoking cessation counselling alone or in combination with nicotine replacement therapy or antidepressants. Comparator interventions included usual care or minimal smoking cessation advice. Trials assessed smoking abstinence or smoking point prevalence at follow-up duration of six months to five years.

Two reviewers independently selected studies for inclusion; disagreements were resolved through discussion with a third reviewer.

Assessment of study quality

Two reviewer independently assessed randomisation, allocation concealment, specification of eligibility criteria, baseline comparability of groups, blinding and use of intention-to-treat analysis. Disagreements were resolved through consensus or referral to a third reviewer.

Data extraction

Dichotomous data were extracted as 2x2 tables and used to calculate odds ratios (OR). Interventions were categorised as low intensity if: they were labelled as such by the authors; the duration of single cessation sessions was ten minutes or less; or the number of sessions was five or less. Other interventions were categorised as high intensity.

One reviewer extracted data and a second reviewer checked the extraction.

Methods of synthesis

A network meta-analysis, which included both direct and indirect comparisons, was conducted using a fixed-effect and a random-coefficient-logistic regression model. Prolonged abstinence was the dependent variable and the different treatment options were the independent variables. This allowed comparison of all treatment options with each other. A random-coefficient model was used to investigate the presence of any additional variation of the treatment effects due to differences across trials.

Results of the review

Eight RCTs (n=7,477 patients) were included in the review. Three trials were considered to be good quality, two moderate quality and three low quality. Only three trials used appropriate randomisation, two reported allocation concealment, four reported blinding of outcome assessors, three reported blinding of treatment providers, three reported blinding of patients and five conducted an intention-to treat analysis.

Smoking cessation (eight RCTs): The most effective smoking cessation treatment was smoking cessation counselling combined with nicotine replacement therapy (OR 5.08, 95% CI 4.32 to 5.97), compared with usual care/no intervention. Smoking cessation counselling plus antidepressants were also significantly more effective than usual care/no intervention (OR 3.32, 95% CI 1.53 to 7.21); both these interventions were significantly more effective than smoking cessation counselling alone. There was no significant difference between smoking cessation counselling plus antidepressants and smoking cessation counselling plus nicotine replacement therapy, or between smoking cessation counselling alone and usual care/no intervention. The odds of prolonged abstinence tended to be increased by high-intensity smoking cessation counselling compared with low-intensity smoking cessation counselling, but these comparisons were only significant for low-intensity smoking cessation counselling plus nicotine replacement therapy versus high-intensity smoking cessation counselling plus nicotine replacement therapy (OR 1.81, 95% CI 1.04 to 3.15).

Mortality (two RCTs): One RCT reported that mortality was significantly reduced after 14.5 years (OR 0.74, 95% CI 0.63 to 0.87) among those who received smoking cessation counselling plus nicotine replacement therapy compared with those receiving usual care. A second RCT also reported lower mortality among those in the intervention group, but this association was not statistically significant and duration of follow-up was only one year.

Authors' conclusions

A small body of evidence suggested that smoking cessation counselling combined with nicotine replacement therapy was more effective than other combinations and single smoking cessation treatments in patients with chronic obstructive pulmonary disease, but substantially more research is needed

CRD commentary

The review addressed a focused question and inclusion criteria were clearly defined in terms of study design, intervention and participants. The literature search was extensive for published studies and included some attempts to locate unpublished studies. Appropriate steps were taken to minimise bias and errors at all stages of the review process.

A detailed quality assessment was conducted using appropriate criteria and the results were clearly presented. A statistically complex meta-analysis was conducted, which appeared appropriate for the study objective.

This was generally a well-conducted review and the authors' conclusions (which acknowledged the limitations of the evidence base) are likely to be reliable.

Implications of the review for practice and research

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

Research: The authors stated that further research is required to improve the still low smoking cessation rates in patients with chronic obstructive pulmonary disease. This should include an investigation into barriers to smoking cessation, high-quality trials with large sample sizes and long follow-up comparing different smoking cessation strategies, and the effects of embedding smoking cessation interventions within patient education programmes.

Funding

Not stated.

Bibliographic details

Strassmann R, Bausch B, Spaar A, Kleijnen J, Braendli O, Puhan MA. Smoking cessation interventions in COPD: a network meta-analysis of randomised trials. European Respiratory Journal 2009; 34(3): 634-640. [PubMed: 19357145]

Indexing Status

Subject indexing assigned by NLM

MeSH

Antidepressive Agents /therapeutic use; Directive Counseling; Humans; Nicotinic Agonists /therapeutic use; Pulmonary Disease, Chronic Obstructive /psychology /rehabilitation; Randomized Controlled Trials as Topic; Smoking Cessation /methods; Treatment Outcome

AccessionNumber

12009109991

Database entry date

23/06/2010

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: 19357145