To evaluate the comparative effectiveness of extrafine hydrofluoroalkane beclometasone (EF HFA-BDP) and other inhaled corticosteroid (ICS) therapy commonly used in the UK, specifically fluticasone (FP) and non-extrafine (NEF) BDP (CFC-BDP and NEF HFA-BDP) in a UK primary care asthma population of current smokers.

Inclusion Criteria:

• Aged 16-70 years
• Current smokers - explicitly coded in patient records or captured in patient questionnaires
• Evidence of asthma diagnosis and current therapy: ≥2 prescriptions for asthma at different points in time during the baseline year ± a diagnostic code for asthma
• On-going asthma therapy: ≥2 prescription for ICS during the outcome period (i.e. ≥1 prescription in addition to IPD prescription)
• ≥2 years continuous data (i.e. ≥1 year of baseline plus ≥1 year of outcome data)

Exclusion Criteria:

Patients will be excluded from the analysis if they have:

• Any chronic respiratory disease other than asthma
• Are prescribed:
• Maintenance oral steroid therapy during the baseline year
• Combination ICS/long-acting beta agonist (LABA) therapy during baseline year or at IPD
• Multiple ICS prescriptions at IPD or immediately before .

Patients are all current smokers ages between 16-70 years with evidence of asthma