Impact of prompt versus delayed initiation of single-inhaler triple therapy among patients with Chronic Obstructive Pulmonary Disease in England in real-world primary and secondary care settings

Study type
Protocol
Date of Approval
Study reference ID
21_000538
Lay Summary

Chronic obstructive pulmonary disease (COPD) is a common, preventable, and treatable condition of the lungs. Patients with COPD experience various symptoms including shortness of breath, coughing and wheezing.

A combination of three types of drug (termed ‘triple therapy’) taken as two or three separate inhalers has been used to treat the most severe patients with COPD for many years, particularly for preventing “flare ups” in symptoms called exacerbations. However, the use of multiple inhalers can be complex and may be cumbersome for patients. This can result in patients not taking the medication according to how they should be taken, a concept known as adherence, resulting in worsening symptoms and increased exacerbations. Therefore, single inhaler triple therapies (SITTs) have recently been developed, whereby the three drugs are combined into a single inhaler, and introduced to improve adherence and reduce the burden on patients.

This study aims to observe whether there are any differences in patient outcomes when initiating patients with COPD on Trelegy (one of two SITTs currently available in the UK) promptly after an exacerbation compared to after a longer period of time has elapsed. This will include describing the number of subsequent exacerbations, the number of hospital readmissions, the need for other healthcare services and the associated costs to the National Health Service. Findings from this study may indicate that early initiation of Trelegy could help to reduce the burden of COPD on the healthcare system and improve patients’ quality of life.

Technical Summary

Aim: To assess whether prompt versus delayed initiation of single inhaler triple therapy (SITT) fluticasone furoate/umeclidinium/vilanterol (FF/UMEC/VI) following a moderate-to-severe acute exacerbation of chronic obstructive pulmonary disease (AECOPD) is associated with differences in subsequent AECOPDs, readmission and healthcare resource utilisation (HCRU)/costs among COPD patients in England.

Objectives: To evaluate i) rate of subsequent AECOPDs (overall, moderate, severe), ii) time-to-first subsequent AECOPD, iii) all-cause/COPD-related readmissions, iv) time-to-first readmission, and v) all-cause/COPD-related HCRU/direct medical costs, among prompt versus delayed initiators of SITT FF/UMEC/VI following an AECOPD. These objectives will be repeated utilising time-to-initiation of FF/UMEC/VI as a continuous variable; the rate of subsequent AECOPDs will also be assessed in patients with prior AECOPDs but no prior triple therapy.

Primary exposure: SITT FF/UMEC/VI initiation post-AECOPD

Outcomes: Rate of subsequent AECOPDs; Time-to-first subsequent AECOPD; Readmissions; Time-to-first readmission; HCRU; Direct medical costs

Methods: A new-user retrospective cohort study using inverse probability of treatment weighting (IPTW) of COPD patients initiating SITT FF/UMEC/VI within 180 days of an AECOPD, using linked CPRD Aurum and Hospital Episode Statistics data. The first/earliest moderate-to-severe AECOPD (Nov-2017‒Mar-2019) will determine the index date. 12+ months AECOPD-free pre-index data will be required. Patients will be categorised as prompt (0-30) or delayed (31-180) initiators dependent on timing of initiation post-AECOPD.

Data analysis: A propensity score (PS) method will be implemented to minimise potential confounding and evaluate average effects in the population. Logistic regression will generate the PS, which will be applied via IPTW. Rate of AECOPDs (events per person-year) will be compared using IPTW-weighted rate ratios (RRs) from negative binomial regression. Time-to-first AECOPD/readmission will be assessed using Kaplan-Meier estimates and compared using IPTW-weighted Cox proportional hazards regression. HCRU and costs (derived via application of unit costs/tariffs) will be compared using IPTW-weighted RRs from negative binomial regression and relative rates from generalised linear model, respectively.

Health Outcomes to be Measured

Rate of subsequent AECOPDs (overall, moderate and severe); Time-to-first subsequent AECOPD (overall, moderate, and severe); Direct medical costs (all-cause and COPD-related); HCRU (all-cause and COPD-related); Hospital readmissions (all-cause and COPD-related); Time-to-first hospital readmission (all-cause and COPD-related)

Collaborators

Kieran Rothnie - Chief Investigator - GlaxoSmithKline Services Unlimited (UK)
Robert Wood - Corresponding Applicant - Adelphi Real World
Afisi Ismaila - Collaborator - GSK
Alexandrosz Czira - Collaborator - GlaxoSmithKline Services Unlimited (UK)
Lucinda Camidge - Collaborator - Adelphi Real World
Lucy Massey - Collaborator - Adelphi Real World
Olivia Massey - Collaborator - Adelphi Real World
Shannon Millard - Collaborator - Adelphi Real World
Victoria Banks - Collaborator - Adelphi Real World

Linkages

HES Accident and Emergency;HES Admitted Patient Care;Patient Level Index of Multiple Deprivation