Asthma is a common lung disease which causes breathing difficulties. It affects around 339 million individuals and causes approximately 461,000 deaths worldwide each year. Patients who have asthma may report chest tightness, wheezing, a cough and symptom flare-ups.
There are a range of drugs that are available for the treatment of asthma in the UK. To help prevent symptom flare-ups patients can be given inhaler treatments containing a combination of two types of drugs, taken together as part of a single inhaler. One type of this inhaler available to patients with asthma in the UK, includes a combination of inflammation preventing steroids (ICS) and long-acting drugs (LABA) which relax the airways; these inhalers are termed ICS/LABA inhalers. All ICS/LABA inhalers are intended to be used daily to prevent symptoms over an extended period of time. There are a range of ICS/LABA therapies available to patients with asthma in the UK, including fluticasone furoate/vilanterol (FF/VI) and budesonide/formoterol (BUD/FOR).
This study aims to compare the effectiveness of FF/VI and BUD/FOR inhalers by looking at how often patients using these therapies experience symptom flare-ups. We will also compare between people taking FF/VI or BUD/FOR inhalers the use of other asthma medication used to relieve symptom flare-ups, the use of healthcare services, and whether patients use their asthma medication according to treatment instructions. The results of this study can be used to better inform treatment decisions for people receiving care for asthma in the UK.
Aim: The aim of this comparative effectiveness research (CER) study is to compare the real-world effectiveness of fluticasone furoate/vilanterol (FF/VI) versus budesonide/formoterol (BUD/FOR) ICS/LABA therapies, among patients with asthma in a general practice cohort in England.
Objectives: To assess the comparative effectiveness of FF/VI and BUD/FOR using the following outcomes: rate of moderate or severe asthma exacerbations (primary objective), rate and time-to-first exacerbation for moderate and severe exacerbations, time-to-first exacerbation, asthma symptom control, healthcare resource utilisation, treatment use, persistence and adherence (secondary objectives). To describe seasonal trends in rate of moderate-to-severe exacerbations and time to ICS dose step-up from index.
Methods: A new-user, active comparator, retrospective cohort study using probability of treatment weighting (IPTW) to adjust for measured confounders will be employed using linked primary and secondary care data. Patients will be indexed on the first/earliest prescription of a single device FF/VI or BUD/FOR inhaler during 1st December 2015 to 28th February 2019, with a minimum of 12 months baseline and maximum of 12 months follow up available. A maximum of 12 months follow-up will be used to assess effectiveness outcomes.
Exposures: Patients with asthma in England newly initiating FF/VI or BUD/FOR ICS/LABA therapies. Respective dosage strata will be compared between treatment groups.
Outcomes: Asthma exacerbations, SABA use, healthcare use treatment patterns, medication use, persistence and adherence.
Data Analysis: IPTW will be implemented following propensity score (PS). Comparisons will be made on both weighted and unweighted treatment cohorts (those newly initiating different ICS/LABAs). Comparisons of rates will be made using rate ratios which will be calculated using a negative binomial model. Time-to-event comparisons will be made using a cox proportional hazards model. For comparisons treatment dose, and adherence and persistence. least squares and logistic regression models will be utilised, respectively. For regression models, 95% CIs and p-values will be generated.
Asthma exacerbations; medication use, adherence and persistence; dosage changes; healthcare resource utilisation (including GP visits, inpatient stays, outpatient visits, and emergency department visits)
Manish Verma - Chief Investigator - GSK India Global Service Private Limited
Alexander Ford - Corresponding Applicant - Adelphi Real World
Arunangshu Biswas - Collaborator - GSK India Global Service Private Limited
Emily Vinall - Collaborator - Adelphi Real World
Ines Palomares - Collaborator - GSK
Neha Shah - Collaborator - GSK
Rosie Wild - Collaborator - Adelphi Real World
Sanchayita Sadhu - Collaborator - GSK
Theo Tritton - Collaborator - Adelphi Real World
HES Accident and Emergency;HES Admitted Patient Care;HES Outpatient;Patient Level Index of Multiple Deprivation