A Retrospective Evaluation of Effectiveness and Cost-effectiveness of Extrafine HFA-BDP Compared With Combination ICS/LABA Therapy in the Management of Asthma in a Representative Population of UK Primary Care Patients

Current asthma guidelines in the UK are underpinned by evidence derived from randomised controlled trials (RCTs). Although RCT data are considered the gold standard, the patients recruited to asthma RCTs are estimated to represent less than 10% of the United Kingdom's (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.

The fixed combination asthma inhalers, FP/SAL (Seretide) and BUD/FOR (Symbicort) are indicated for use in asthma when adequate asthma control is not achieved with low/medium dose ICS therapy and as-needed (prn) reliever therapy (a short-acting beta-agonist [SABA]). Fixed combination inhalers are also indicated in patients already adequately controlled on separate ICS/LABA therapy. However, emerging trends in asthma prescribing indicate increasing use of add-on therapies (particularly in the form of combination inhalers) in the early stages of asthma therapy, even as first-line therapy.

In practice, there is significant pressure (supported by asthma guidelines) to use the least expensive, effective inhaled therapies available. While the effect of increased use of add-on and combination therapies in terms of patient benefits remains uncertain, the impact on the UK's National Health Service (NHS) treatment costs is unequivocal.

Short, randomised trials of the effectiveness of asthma monotherapies have demonstrated that extrafine HFA-BDP is at least as effective at half the dose as BDP pMDI, and equivalent to same-dose FP pMDI. There is also evidence to suggest that extrafine HFA-BDP optimises deposition in the lung and affords greater tolerance of poor coordination of breathing and inhaler actuation. In addition, one long-term, prospective, randomised, open-labelled trial comparing extrafine HFA-BDP with BDP over the course of one year demonstrated greater improvements in symptom-free days and quality of life in the extrafine HFA-BDP treatment group, at a lower cost per symptom-free day.

The hypothesis for this study, therefore, is that extrafine HFA-BDP may be a suitable, and cost-effective, alternative to combination therapy (as fixed or separate inhalers) in children and adults with evidence of persistent asthma.