Comparison of ﬁxed-dose combinations for asthma 1871 symptom relief as needed (1,2). Clinical trials have demonstrated that, in patients in whom asthma is not controlled with low-dose ICS, the combination of an ICS and a long-acting b2-agonist (LABA) improves asthma control more effectively than higher doses of ICS alone (4–7). This combination is now the recom- mended maintenance therapy for patients stepping up from low-dose ICS (1,2). Fixed-dose combination inhalers have been developed, which offer improved convenience over ICS and LABA administered in separate devices and ensure better long-term compli- ance to anti-inﬂammatory therapy (8). Two previous database studies indicated that combination products improve both compliance and treatment outcomes compared with the concurrent administration of individual products via separate inhalers (9,10). The two most commonly used ﬁxed combination products, budesonide ⁄ formoterol (Symbicort , AstraZeneca, Lund, Sweden) and salmeterol ⁄ ﬂutica- sone (Seretide , GlaxoSmithKline, Uxbridge, UK or Viani , GlaxoSmithKline), have both been shown to be highly effective in patients with persistent asthma that is uncontrolled with ICS alone (6,11–15). Randomised controlled studies in moderate-to-severe asthma have shown similar daily or weekly control and overall exacerbation rates for both combinations when used as ﬁxed-dose maintenance therapy (16– 18). Nevertheless, in the study by Kuna and col- leagues and a recent meta-analysis of three clinical trials, including over 4000 patients, it was found that the risk or rate of exacerbations requiring hospitali- sations ⁄ emergency treatments was lower with sus- tained ﬁxed-dose budesonide ⁄ formoterol than with sustained ﬁxed-dose salmeterol ⁄ ﬂuticasone (18–20). This important efﬁcacy difference was consistent in all three of the individual studies included in the analysis. Two recent meta-analyses also indicate that these two combinations may have different effects on asthma-related hospitalisations. In an analysis assess- ing the safety of formoterol administered in combi- nation with an ICS in 18 double-blind clinical studies, fewer asthma-related hospitalisations and asthma-related serious adverse events were observed in the formoterol ⁄ ICS group compared with the ICS-alone control group (21). These results were independent of the ICS dose in the control group. In contrast, an analysis of 52 clinical studies of salme- terol showed no difference in asthma-related hospi- talisations when salmeterol was added to an ICS compared with ICS alone (22). Thus, it appears that combination therapies may not have the same level of efﬁcacy across all outcome measures important in asthma management. It is not certain if the reduced risk of requiring hospitalisation ⁄ emergency treatment with budeso- nide ⁄ formoterol compared with salmeterol ⁄ ﬂutica- sone in meta-analyses of randomised controlled trials is likely to be seen in the normal clinical setting. In this case, database studies can provide valuable infor- mation on how these commonly used combination therapies affect cost-driving outcomes, such as exac- erbations, in everyday practice. Such analyses are also important for establishing the overall relative cost-effectiveness of initiating treatment with combi- nations of budesonide ⁄ formoterol or salmeterol ⁄ ﬂuticasone in asthma patients. The relative effective- ness and cost-effectiveness of initiating maintenance therapy with budesonide ⁄ formoterol and salmeter- ol ⁄ ﬂuticasone under standard clinical conditions in Germany is not known. The aim of this retrospective database cohort study was to compare treatment outcomes and healthcare costs in the year after the initiation of maintenance treatment with budesonide ⁄ formoterol or salmeterol ⁄ ﬂuticasone in a German healthcare setting. Methods Sources of data This study was a retrospective database cohort study carried out using data obtained from the IMS Dis- ease Analyzer database (http://www.imshealth.com). This is a database that captures real-life, longitudinal, anonymised data on patients and prescribers across Europe. In Germany, approximately 2000 physicians record data on 10 million patients. The data recorded include patient demographics, physician characteristics, prescriptions, hospital admissions and specialist referrals. Patient population The cohorts identiﬁed for the study included patients who initiated maintenance treatment with budeso- nide ⁄ formoterol or salmeterol ⁄ ﬂuticasone between June 2001 and June 2005. Budesonide ⁄ formoterol is reported to be effective when used as both mainte- nance and reliever therapy compared with traditional ICS ⁄ LABA combinations plus SABA (18,23,24). However, during the time period when the data used in this study was recorded, budesonide ⁄ formoterol was approved for use as maintenance treatment only. In this study, the index date was deﬁned as the date of their ﬁrst prescription of ICS ⁄ LABA combination. Eligible patients were over 12 years of age, had a diagnosis of asthma (ICD-10 codes J45–46) and con- tinuous enrolment in the database from 12 months prior to the index date to 12 months after the index date (IMS data was collected between June 2000 and June 2006). Patients with diagnosed chronic obstruc- tive pulmonary disease or use of ICS ⁄ LABA prior to ª 2008 Ingenix Pharmaceutical Services (UK) Ltd. Journal compilation ª 2008 Blackwell Publishing Ltd Int J Clin Pract, December 2008, 62, 12, 1870–1879