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Evidence toolbox - Is a combined inhaler best for copd?

Summary of a Cochrane review that could be relevant to your next consultation

Summary of a Cochrane review that could be relevant to your next consultation

Is a combined steroid and long-acting ß-agonist in one inhaler better than a long-acting ß-agonist for chronic obstructive pulmonary disease?

The co-administration of inhaled corticosteroids and long-acting ß-agonists in a combined inhaler is intended to facilitate adherence to medication regimens, and to improve efficacy in COPD. In this review they are compared with mono-component long-acting ß-agonists.

We searched the Cochrane Airways Group Specialised Register of trials. The date of the most recent search was April 2007.

Studies were included if they were randomised and double-blind. Studies could compare a combined inhaled steroid and long-acting ß-agonist preparation with component long-acting ß-agonist preparation.

Two reviewers independently assessed trial quality and extracted data. The primary outcomes were exacerbations, mortality and pneumonia, with health-related quality of life (measured by validated scales), lung function and side-effects as secondary outcomes. Dichotomous data were analysed as fixed effect odds ratios (OR), and continuous data as mean differences and 95% confidence intervals (CI). Sensitivity analysis was performed by combining data with a random effects model.

Ten studies of good methodological quality met the inclusion criteria, randomising 7,598 participants with severe chronic obstructive pulmonary disease. Eight studies assessed fluticasone-salmeterol, and two studies budesonide-formoterol (BDF). The exacerbation rates with combined inhalers were reduced in comparison with long-acting ß-agonists alone (rate ratio 0.82, 95% CI 0.78 to 0.88). There was no significant difference in mortality between combined inhalers and long-acting ß-agonists alone. Pneumonia occurred more commonly with combined inhalers (OR 1.62; 95% CI 1.35 to 1.94). There was no significant difference in terms of hospitalisations, although the two studies contributing data to this outcome may have been drawn from differing populations. Combination was more effective than long-acting ß-agonist in improving quality of life measured by the St George Respiratory Questionnaire, and the Chronic Respiratory Questionnaire, and pre-dose and post-dose FEV1.

Authors' conclusions
Combination therapy was more effective than long-acting ß-agonists in reducing exacerbation rates, although the evidence for the effects on hospitalisations was mixed, and requires further exploration. No significant impact on mortality was found even with additional information from the TORCH trial. The superiority of combination inhalers should be viewed against the increased risk of side-effects, particularly pneumonia. Additional studies on BDF are required and more information would be useful of the relative benefits and adverse event rates with different doses of inhaled steroids.

Nannini LJ, Cates CJ, Lasserson TJ, Poole P. Combined corticosteroid and long-acting ß-agonist in one inhaler versus long-acting ß-agonists for chronic obstructive pulmonary disease. Cochrane Database of Systematic Reviews 2007, Issue 4. Art no: CD006829. DOI: 10.1002/14651858.

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Combined inhaler

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