Device Mixing in Asthma, 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 Easi-breathe® (EB) -
      beclometasone dipropionate (BDP) breath-actuated inhaler (BAI) - and as-needed (prn) reliever
      medication (short-acting beta2-agonist [SABA] therapy) via either a BAI (i.e. Easi-breathe®
      [EB] salbutamol) or via a pressurised metered dose inhaler (MDI) (e.g. MDI salbutamol).
    

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.

      Inhalation therapy is the cornerstone of asthma treatment, used for the delivery of
      'reliever' bronchodilator therapy (e.g. salbutamol) as well as anti-inflammatory
      corticosteroid 'maintenance' or 'controller' therapy. Currently available inhaler devices
      include MDIs, breath-actuated MDIs (BAIs), and dry powder inhalers (DPIs). Both BAIs and DPIs
      are actuated by the patient's inhalation manoeuvre, while MDIs are actuated by the patient's
      pressing of a button, which must thus be coordinated with inhalation. The clinical
      effectiveness of inhalation therapy derives from delivery of drug to the target sites in the
      lungs, and evidence is mounting that suboptimal use of inhaler devices is a common problem
      contributing to compromised asthma control for many patients. Indeed, decreased asthma
      control has been linked to the number of mistakes when using MDIs for delivering inhaled
      corticosteroids (ICS).

      There is also evidence that the ability of patients to use the different inhaler device types
      is variable. Nonetheless, recent reviews of RCTs, while recognising the importance of inhaler
      technique, have concluded that inhaler devices do not differ significantly in efficacy and
      that the cheapest inhaler device should be used. However, as results are based on RCTs they
      should be applied with care in light of the aforementioned issues around external validity of
      RCTs and the ability to extrapolate their findings across a broad patient population.
      Moreover, patients enrolled in RCTs typically receive extensive training and must demonstrate
      and maintain proper inhaler technique, seldom accomplished in a real-world setting.

      The aim of this study is to compare the absolute and relative effectiveness of ICS
      (maintenance) plus SABA (reliever) therapy delivered via same-type devices (namely BDP via EB
      plus salbutamol via EB [BAI]) and that delivered via different device types (i.e. BDP via EB
      [BAI] plus SABA via MDI) in a real-life, representative, UK primary care asthma population.
    

Intervention name(s): Initiation of beclometasone via the Easibreathe device plus salbutamol via the Easibreathe device; Initiation of beclometasone via the Easibreathe device plus salbutamol via and MDI device; Increase of beclometasone via the Easibreathe device plus salbutamol via the Easibreathe device; Increase of beclometasone via the Easibreathe device plus salbutamol via an MDI
Intervention type(s): Drug; Drug; Drug; Drug
Intervention MeSH terms: Beclomethasone; Albuterol
Observational model: Cohort
Time perspective: Retrospective
Sampling method: Non-Probability Sample
Study population: 
        Asthma patients on SABA therapy (any available) monotherapy who, at the index date, either:

        (i) IPDI: initiate ICS therapy as BDP EB at the index date and also receive reliever
        therapy as either*:

          -  Salbutamol EB, or

          -  Salbutamol MDI, OR, who (ii) IPDA: receive a recorded increase in ICS therapy as BDP
             EB at the index date and also receive reliever therapy as either*:

          -  Salbutamol EB, or

          -  Salbutamol MDI.
      
Keywords: Primary care; asthma management; inhaler device; maintenance therapy; reliever therapy; Easibreathe salbutamol