1878 Comparison of ﬁxed-dose combinations for asthma more effective than either ICS alone or separately administered ICS and LABA (8–10). This database analysis of ﬁxed-dose ICS ⁄ LABA combinations adds to a growing body of evidence suggesting that there may be efﬁcacy differences between budesonide ⁄ for- moterol and salmeterol ⁄ ﬂuticasone across certain cost-driving outcomes. The results suggest that, in a German healthcare setting, better outcomes can be achieved at a lower overall cost if patients are treated with budesonide ⁄ formoterol instead of salmeterol ⁄ ﬂuticasone. The economic cost of asthma is considerable both in terms of direct medical costs (such as hospital admissions and cost of pharmaceuticals) and indirect costs (such as time lost from work and premature death). Ineffective management of asthma can increase these costs, and the overall cost-effectiveness of new therapies is an important consideration. Eco- nomic analyses in Sweden have shown that combin- ing budesonide and formoterol in one device may be cost-effective compared with the two agents adminis- tered separately (25,26). This study is the ﬁrst of its kind to compare the cost-effectiveness of budeso- nide ⁄ formoterol and salmeterol ⁄ ﬂuticasone using a German database analysis. The analysis indicates that, relative to the use of salmeterol ⁄ ﬂuticasone, budeso- nide ⁄ formoterol treatment is less costly and is associ- ated with a greater rate of treatment success in the German healthcare setting. The difference in cost appeared to be driven by fewer physician visits and lower expenditure on medications in the treatment practices where budesonide ⁄ formoterol was com- monly used than in the practices where salmeter- ol ⁄ ﬂuticasone was used. In database surveys, both the clinician and the treatment are likely to inﬂuence outcomes. Of note, in this analysis there were some differences between the two treatment groups in terms of lead physician type and insurance status. A higher proportion of patients in the budesonide ⁄ for- moterol group were followed at a GP-lead clinic, while a higher proportion of the salmeterol ⁄ ﬂutica- sone group were followed at a specialist-lead clinic. Although statistically signiﬁcant, these differences were small and have been controlled for through the use of regression analyses. The fact that a high proportion of patients did not continue treatment with ICS ⁄ LABA for the whole study period, particularly in the budesonide ⁄ formo- terol group, commands caution in interpreting the results. However, the effect of budesonide ⁄ formoterol on treatment success in the subgroup of patients who did not renew their initial prescription (OR: 1.422; p = 0.0333) was similar to the effect estimated in the whole sample, using logistic regression. Among patients with at least one prescription renewal within 4 months of the index date, the prob- ability of treatment success was also higher for those treated with budesonide ⁄ formoterol, although the corresponding effect was not statistically signiﬁcant. The ICS ⁄ LABA prescription renewal rates observed in this analysis are similar to those reported in a pharmacy database study investigating salmeter- ol ⁄ ﬂuticasone adherence and persistence in 5504 patients in the USA (27). More than half the patients ﬁlled a 30-day prescription only once over a 1-year interval, suggesting that adherence to ICS ⁄ LABA combinations may be considerably lower than those reported in clinical trials. Evidence also indicates that, in ‘real-life’, adherence to asthma therapy is greater among patients using ﬁxed-dose combination inhalers compared with those prescribed separate ICS and LABA inhalers (8). As with all database studies there are several other limitations not usually encountered in controlled clinical trials that must be considered. Lack of fol- low-up between practices and the absence of any record of medications prescribed by specialists could lead to underestimation of prescriptions. However, this is unlikely to account for the differences observed between treatment groups in this compara- tive study as pre-index referrals and asthma-related prescriptions were similar between the two groups. Missing diagnoses and the use of algorithms to iden- tify asthma-related events may also affect the results; however, this is also unlikely to have resulted in any signiﬁcant bias in this study because proportions of missing diagnoses between treatment groups were similar. Of note, the probability of success was signif- icantly higher in the budesonide ⁄ formoterol group in analyses using other variants of the deﬁnition of treatment success, taking into account events not related to asthma (results not reported). Further- more, costs were lower in the budesonide ⁄ formoterol group regardless of whether costs unrelated to asthma, including costs for other medications and non-asthma-related physician visits, were included or not. Two key objectives listed in guidelines for the suc- cessful management of chronic asthma are to achieve and maintain control of symptoms and to reduce or prevent asthma exacerbations. The results of this study suggest that in the German healthcare setting these goals are achieved more often in patients prescribed budesonide ⁄ formoterol than in patients prescribed salmeterol ⁄ ﬂuticasone, and that budeso- nide ⁄ formoterol appears to represent a more cost-effective option based on the available evidence. Although the cohorts appeared to be well matched at baseline, the results should be interpreted with caution given the observational nature of the study. ª 2008 Ingenix Pharmaceutical Services (UK) Ltd. Journal compilation ª 2008 Blackwell Publishing Ltd Int J Clin Pract, December 2008, 62, 12, 1870–1879