Qvar Versus Clenil, a General Practice Research Database Study
Condition: Asthma
MeSH terms: Asthma
Study type: Observational

Summary: 
      This study will compare the absolute and relative effectiveness of asthma management in
      patients on inhaled corticosteroid (ICS) maintenance therapy as either extra-fine-particle or
      larger-particle formulation beclomethasone dipropionate (BDP) via metered-dose inhalers
      (MDIs) using the propellant hydrofluoroalkane propellant (HFA-BDP), namely Qvar® MDI compared
      with Clenil® MDI.
    

Detailed description: 
      Current asthma guidelines in the UK are underpinned by evidence derived from randomised
      controlled trials (RCTs). Although RCT data are considered the gold standard, patients
      recruited to asthma RCTs are estimated to represent less than 10% of the UK's asthma
      population. The poor representation of the asthma population is due to a number of factors,
      such as tightly-controlled inclusion criteria for RCTs. There is, therefore, a need for more
      representative RCTs and real-life observational studies to inform existing guidelines and
      help optimise asthma outcomes.

      In response to the Montreal Protocol's ruling to phase out ozone-depleting chlorofluorocarbon
      (CFC) propellants in asthma inhalers, several hydrofluoroalkane-134a-propellant (HFA-)
      formulations of BDP have been developed. Two branded generic formulations currently available
      in the UK are Qvar® (Teva Pharmaceutical Industries Ltd) - an extra-fine-particle (~1.1
      microns) HFA-BDP (solution) formulation and Clenil® (Chiesi Limited) - a larger particle
      (~2.9 microns) HFA-BDP (suspension) formulation.

      The extra-fine particle formulation HFA-BDP formulation (Qvar®) has been shown to improve
      total and small airway deposition relative to CFC-BDP. As a result of the more even
      distribution through both the large and small airways of the lungs and data from short-term
      randomised clinical trials (RCTs), Qvar® dosing is recommended at approximately one half the
      dose of traditional CFC-BDP (average particle size ~3.5 microns). However, the
      larger-particle Clenil® is recommended for prescribing at the same dose as traditional
      CFC-BDP.

      Further studies are required to understand whether the differences in particle size and
      airway distribution have an impact on asthma outcomes over the long-term.

      This observational study will investigate the real-world effectiveness of extra-fine HFA-BDP
      (Qvar®) as compared with larger-particle HFA-BDP (Clenil®) in patients with asthma who: were
      new to ICS therapy; received an increase in their ICS dose, or switched / changed baseline
      ICS therapy to HFA-BDP with no change in BDP-equivalent ICS dose. We hypothesise that
      differences in effectiveness might become apparent over the longer term through a
      retrospective database analysis of one-year outcomes for the diverse patient population seen
      in primary care.
    

Intervention name(s): extra fine particle hydrofluoroalkane beclomethasone dipropionate via metered dose inhaler; standard particle particle hydrofluoroalkane beclomethasone dipropionate via metered dose inhaler
Intervention type(s): Drug; Drug
Intervention description(s): IPDI cohort intervention = initiation of intervention drug; IPDS cohort intervention = switching from baseline inhaled corticosteroid therapy to intervention drug without a change in baseline inhaled corticosteroid dose; IPDA cohort intervention = increase in baseline inhaled corticosteroid drug as intervention drug; IPDI cohort intervention = initiation of intervention drug; IPDS cohort intervention = switching from baseline inhaled corticosteroid therapy to intervention drug without a change in baseline inhaled corticosteroid dose; IPDA cohort intervention = increase in baseline inhaled corticosteroid drug as intervention drug
Other intervention name(s): Qvar; Fostair
Intervention MeSH terms: Beclomethasone
Observational model: Case-Control
Time perspective: Retrospective
Sampling method: Non-Probability Sample
Study population: 
        All patients are aged between 4-80 years and have evidence of asthma and subsequent
        therapy.
      
Keywords: Primary Care; Particle size; beclomethasone dipropionate; Asthma Management; Maintenance Therapy; Metered-Dose Inhaler