OBJECTIVES: A large scale database analysis was undertaken comparing resource use in UK primary care patients receiving inhaled steroids via MDI and BOI. The aim was to compare resource use over a two-year period of patients receiving inhaled beclometasone via MDI, with patients utilising BOI. METHODS: Data was extracted from Din-Link patient-level databases to compare resource utilisation over 24 months in patients receiving BOI with those on standard MDI. Entry criteria were: 1) Diagnosis of asthma, 2) Receiving beclometasone via MDI; and 3) No other preventer medication. Index event was change to a different MDI or BOI. Key measures included annualised average costs of: i) Primary care consultation for asthma; ii) Anti-asthma prescriptions; iii) Spacer devices; and iv) Hospital referral and admissions for asthma. RESULTS: Primary care medication costs for child patients were £108.62 (BAI) versus £77.23(MDI) and for adults were £79.35 (BAI) versus £92.76 (MDI). Non-medication resource use for child patients over the period was: GP consultation (£63.00 BAI vs £102.68 MDI); outpatient attendance (£18.43 BAI vs £22.62 MDI); hospital admissions (£0.00 BAI vs £15.46 MDI). Non-medication resource use for adult patients was: GP consultation (£82.75 BAI vs £114.20 MDI); outpatient attendance (£10.75 BAI vs £12.30 MDI); hospital admissions (£28.35 BAI vs £21.39 MDI). Total asthma costs over the two year period for BAI patients were £190.05 (children) and £201.20 (adults). Comparative figures for MDI patients were £217.99 (children) and £240.56 (adults). CONCLUSION: The additional acquisition cost associated with BOI appears to be offset by enhanced clinical effectiveness. A trend in cost effectiveness emerged in favour of BOI versus the equivalent MDI for both children and adults.