1876 Comparison of ﬁxed-dose combinations for asthma Table 4 Reasons for failure to meet primary or secondary criteria for treatment success Reason (% of all patients) SABA use > 0.5 to £ 2 doses ⁄ day > 2 doses ⁄ day Addition of other asthma medication* between week 10 and week 52 after index date Switch from ICS + LABA combination to another OCS prescriptions 1–2 prescription > 2 prescriptions Referrals related to asthma 1 referral > 2 referrals Hospitalisation related to asthma 1 hospitalisation > 2 hospitalisations success when applying the secondary deﬁnition (OR: 1.26; p = 0.0119). Subgroup analyses were conducted according to prescription renewal of ICS ⁄ LABA combination treatment. The logistic regression model for the primary deﬁnition of treatment success showed a signiﬁcant treatment effect with budesonide ⁄ formo- terol for the subgroup of the 1169 patients who did not renew their initial prescription (OR: 1.422; p = 0.0333) and for the 1269 patients with at least two prescriptions (OR: 1.426; p = 0.0064). For the 586 patients with a prescription renewal within 4 months of index date the OR was 1.214, which did not reach statistical signiﬁcance (p = 0.3011). Other treatment outcomes A signiﬁcantly higher number of severe exacerbations was observed among patients treated with salmeter- ol ⁄ ﬂuticasone compared with budesonide ⁄ formoterol in the unadjusted analysis (0.1955 vs. 0.103 episodes per patient per year; p = 0.0018; Table 5). Linear regression analysis (adjusted for pre-index ICS, LABA and SABA use, gender and numbers of exacerbations, OCS prescriptions, referrals and hospitalisations over the pre-index period) indicated that budesonide ⁄ for- moterol reduced the number of severe exacerbations by 33.4% compared with salmeterol ⁄ ﬂuticasone (p = 0.0123). There was no statistically signiﬁcant *Leukotriene antagonist, IgE (omalizumab), anticholinergic (ipratropium, ipratropium + fenoterol combination), theophylline, combina- tion cromolyn ⁄ reproterol. Not more than 11% of failures in either group were associated with any one medication. BUD ⁄ FORM, budesonide ⁄ formoterol; ICS, inhaled corticosteroid; LABA, long-acting b2-agonist; OCS, oral corticosteroid; SABA, short-acting b2-agonist; SAL ⁄ FLU, salmeterol ⁄ ﬂuticasone. SAL ⁄ FLU group (n = 982) BUD ⁄ FORM group (n = 1456) 15.7 8.8 25.4 7.0 5.2 2.0 5.7 9.9 1.1 0.2 15.2 7.8 20.2 3.6 3.8 0.9 3.9 9.0 0.3 0.2 Figure 3 Relative probability of full treatment success. Values to the right of the vertical line indicate a higher probability of full treatment success with budesonide ⁄ formoterol compared with salmeterol ⁄ ﬂuticasone. The ﬁlled circles represent the point estimate for the odds ratios (OR) and the horizontal lines the range of the conﬁdence intervals. The regression models used to derive the adjusted OR included pre-index inhaled corticosteroid (ICS), long-acting b2- agonist (LABA) and short-acting b2-agonist (SABA) use for the primary deﬁnition and pre-index ICS, LABA and SABA use, age and physician speciality for the secondary deﬁnition ª 2008 Ingenix Pharmaceutical Services (UK) Ltd. Journal compilation ª 2008 Blackwell Publishing Ltd Int J Clin Pract, December 2008, 62, 12, 1870–1879