Budesonide/formoterol maintenance and reliever therapy (Symbicort SMART) reduces asthma exacerbations and symptoms versus fixed-dose regimens plus short-acting beta(2)-agonists (SABA) in double-blind trials. Information is lacking regarding its effectiveness versus conventional best practice (CBP). This pooled analysis of six 6-month, randomized, open-label studies examined asthma control and exacerbation risk in asthmatics (aged> or =12 years). Patients (N=7855) symptomatic on inhaled corticosteroids (ICS) or stable/symptomatic on ICS/long-acting beta(2)-agonists (LABA) received budesonide/formoterol maintenance and reliever therapy (160/4.5microg bid and as needed) or CBP (ICS or ICS/LABA+/-other agents at an approved dose plus as-needed SABA). Overall asthma control was assessed comparing the incidence of exacerbations and levels of asthma control using the asthma control questionnaire (ACQ). Budesonide/formoterol maintenance and reliever therapy did not significantly reduce time to first severe exacerbation (primary variable) versus CBP (P=0.062). However, patients in this group experienced 15% fewer exacerbations (0.20 versus 0.24/patient/year; P=0.021) and used 27% less ICS (P<0.0001). Odds of remaining well controlled (ACQ< or =0.75) over 6 months were higher with budesonide/formoterol maintenance and reliever therapy versus CBP (45% versus 41%, odds ratio [OR] 1.29; P<0.01) while risk of remaining uncontrolled decreased (25% versus 29%, OR 0.81; P<0.01). Budesonide/formoterol maintenance and reliever therapy improves key aspects of asthma control versus physicians' choice of CBP.