Real-world Effectiveness and Cost-effectiveness of Leading Inhaled Corticosteroids in Asthma Management (QvarAsthma)

• Proxy asthma control [ Time Frame: One-year outcome period ] [ Designated as safety issue: No ]

  Primary composite measure asthma control defined as:

  • No recorded hospital attendance for asthma including admission, Accident & Emergency (A&E) attendance, out of hours attendance or Out-Patient Department (OPD) attendance, AND
  • No prescriptions for oral steroid, AND
  • No consultations, hospital admissions or A&E attendance for lower respiratory tract infections (LRTI) requiring antibiotics.
  
  

• Revised asthma control [ Time Frame: One-year outcome period ] [ Designated as safety issue: No ]

  A revised definition of proxy asthma control for sensitivity analysis was defined as:

  • No recorded hospital attendance for asthma including admission, A&E attendance, out of hours attendance or OPD attendance, AND
  • No prescriptions for oral steroid, AND
  • No consultations, hospital admissions or A&E attendance for lower respiratory tract infections (LRTI) requiring antibiotics
  • Average daily prescribed dose of salbutamol of no more than 200mcg and terbutaline 500mcg.
  
  
• Disaggregated components of the primary control outcome [ Time Frame: One-year outcome period ] [ Designated as safety issue: No ]
  • Hospital admissions for asthma
  • Consultations and hospital attendances for LRTI requiring antibiotics
  • Prescriptions for oral steroids
  • SABA use
  
  
• Time to the first asthma exacerbation [ Time Frame: One-year outcome period ] [ Designated as safety issue: No ]

  Where an exacerbation is defined as:

  • An occurrence of unscheduled hospital admission/A&E attendances for asthma AND/OR
  • Use of oral steroids.
  
  
• Success of the therapeutic regimen [ Time Frame: One-year outcome period ] [ Designated as safety issue: No ]

  Defined as:

  • Exacerbation AND/OR
  • Increase in dose of ICS AND/OR
  • Change in ICS drug type AND/OR
  • Change in delivery device AND/OR
  • Use of additional therapy as defined by: LABAs, oral steroids, theophylline, leukotriene receptor antagonists (LTRAs)
  
  
• Use of anti-fungals [ Time Frame: One-year ] [ Designated as safety issue: No ]
  defined as incidences of definite oral candidiasis
  
  
• Daily dose of ICS (BDP equivalent) at week 52 compared with week 0 and proportion on original dose of BDP Daily dose* of ICS (BDP equivalent) at week 52 compared with week 0 and proportion on original dose of BDP. [ Time Frame: One-year outcome period ] [ Designated as safety issue: No ]
  BDP-equivalent dose were calculated by multiplying the Qvar and FP doses by a factor of 2. The dose at week 52 was compared with that at week 0 in order to identify the proportion of original (week 0) ICS dose.
  
  

While current UK asthma guidelines are underpinned with evidence from RCTs, much of this evidence has been undertaken in patients who are not representative of the majority of the current UK asthma population. In fact it has been estimated that fewer than 10% of the patients seen in everyday clinical practice would be eligible for inclusion in such trials. 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 and observational studies to inform existing guidelines and help optimise asthma outcomes. A more holistic approach to respiratory research would see RCT evidence complimented by "real-life" data from pragmatic trials and observational studies.

A number of trends are emerged in asthma prescribing that warrant further investigation to ascertain their benefit to both the patient and the NHS. In particular, significant pressure exists to use the cheapest inhaler devices and formulations. An analysis of a pragmatic trial of Qvar versus standard CFC-BDP undertaken by Research in Real Life suggested that Qvar may be offer greater effectiveness in.5,6 In light of these data, the following report details the findings of a study designed to examine the effectiveness of Qvar in real-life clinical practice using the General Practice Research Database (GPRD).