Combination fluticasone and salmeterol versus fixed dose combination budesonide and formoterol for chronic asthma in adults and children

Background Long-acting beta-agonists are a common second line treatment in people with asthma inadequately controlled with inhaled corticosteroids. Single device inhalers combine a long-acting beta-agonist with an inhaled steroid delivering both drugs as a maintenance treatment regimen. This updated review compares two fixed-dose options, fluticasone/salmeterol FP/SALand budesonide/formoterol, since this comparison represents a common therapeutic choice. Objectives To assess the relative effects of fluticasone/salmeterol and budesonide/formoterol in people with asthma. Search methods We searched the Cochrane Airways Group register of trials with prespecified terms. We performed additional hand searching of manufacturers' web sites and online trial registries. Search results are current to June 2011. Selection criteria We included randomised studies comparing fixed dose fluticasone/salmeterol and budesonide/formoterol in adults or children with a diagnosis of asthma. Treatment in the studies had to last for a minimum of 12 weeks. Data collection and analysis Two authors independently assessed studies for inclusion in the review. We combined continuous data outcomes with a mean difference (MD), and dichotomous data outcomes with an odds ratio (OR). We assessed the quality of the evidence using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) system. Main results Five studies met the review entry criteria (5537 adults). Study populations entered the studies having previously been treated with inhaled steroids and had moderate or mild airway obstruction (mean FEV1 predicted between 65% and 84% at baseline). Most of the studies assessed treatment over a period of six months. The studies were at a low risk of selection and performance/detection bias, although we could not determine whether missing data had an impact on the results. Availablility of outcome data was satisfactory. Primary outcomes The odds ratio for exacerbations requiring oral steroids was lower with fluticasone/salmeterol but did not reach statistical significance (OR 0.89, 95% confidence interval (CI) 0.74 to 1.07, four studies, N = 4949). With an assumed risk with budesonide/formoterol of 106/1000 participants requiring oral steroids, treatment with fluticasone/salmeterol would lead to between 25 fewer and seven more people per 1000 experiencing a course of oral steroids. Although the odds of hospital admission was higher with fluticasone/salmeterol, this did not reach statistical significance (OR 1.29, 95% CI 0.68 to 2.47, four studies, 4879 participants). With an assumed risk in the budesonide/formoterol of 7/1000, between two fewer and 10 more people per 1000 would be hospitalised on fluticasone/salmeterol. The odds of a serious adverse event related to asthma was higher with fluticasone/salmeterol but did not differ significantly between treatments (OR 1.47, 95% CI 0.75 to 2.86, three studies, 4054 participants). With an assumed risk in the budesonide/formoterol of 7/1000, between two fewer and 13 more people per 1000 would experience a serious adverse event on fluticasone/salmeterol. Secondary outcomes Lung function outcomes, symptoms, rescue medication, composite of exacerbations leading to either emergency department visit or hospital admission, withdrawals and adverse events did not differ statistically between treatments. Assessment of quality of life was limited to two studies, both of which gave results that did not reach statistical significance. One study reported one death out of 1000 participants on fluticasone/salmeterol and no deaths in a similar number of participants treated with budesonide/formoterol. No deaths were reported in the other studies. Authors' conclusions Statistical imprecision in the effect estimates for exacerbations and serious adverse events do not enable us to conclude that either therapy is superior. The uncertainty around the effect estimates justify further trials to provide more definitive conclusions; the overall quality of evidence based on GRADE recommendations for the three primary outcomes and withdrawals due to serious adverse events was moderate. We rated the quality of evidence for mortality to be low. Results for lung function outcomes showed that the drugs were sufficiently similar that further research is unlikely to change the effects. No trials were identified in the under-12s and research in this population is a high priority. Evaluation of quality of life is a priority for future research.