Chronic obstructive pulmonary disease (COPD) is associated with a high burden of disease: in particular, patients may suffer from "exacerbations", when symptoms, such as chest tightness and shortness of breath, rapidly become worse. Exacerbations often require admission to hospital. Furthermore, our previous work showed that more than one third (37%) of patients who were discharged from admission to hospital for COPD exacerbation was readmitted for the same reason within 1 year and 12% within 4 weeks, despite extensive drug treatment to prevent exacerbations. Knowing which patients are at most risk is highly useful if COPD management is to be improved. Particularly patients with COPD who have high counts of white blood cells called eosinophils were found to be at high risk of exacerbations probably due to the unresolved inflammation orchestrated by these cells. These patients could potentially be targeted with biologic therapy.
This study will characterise a large sample of UK patients with COPD with specific focus on patients who are at risk of frequent exacerbations in spite of inhaler therapy.
Objective 1: To identify and characterise COPD patients that can be the target for biologic therapies, by allocating and characterising the following four study cohorts:
1. General population of patients with 'active' COPD, who had >/=1 prescription for maintenance inhaled therapy
2. Patients with 'active' GOLD grade C/D (high risk) on dual or triple therapy
3. Patients with 'active' GOLD grade C/D (high risk) on triple therapy
4. 'End-stage of COPD' cohort: patients with 'active' COPD who died before the last extraction from general practice and who had >/=1 prescription for maintenance therapy within the period of 12 months prior to death
Objective 2: To describe the characteristics of subgroups of patients with 'active' GOLD grade C/D on dual or triple therapy (cohorts 2 and 3), defined by the following characteristics and combinations of (some of) these characteristics:
1. Rate of COPD exacerbations
2. Occurrence of COPD-related hospitalisation
3. Average oral corticosteroids (OCS) exposure
4. Blood eosinophil count (BEC)
5. Smoking status
6. Presence of airway obstruction (FEV1/FVC <0.70)
7. Number of years with >/=1 or >/=2 exacerbations in the previous 10 years (subpopulation with complete data)
Objective 3: To assess outcomes and health care resource utilisation (HCRU) during one-year of follow-up in cohorts 1-3
Objective 4: To assess the all-cause and COPD-related mortality during one-year of follow-up in cohorts 1-3 using linked data to the Office for National Statistics (ONS).
The index date will be a randomly selected date of a prescription for maintenance therapy for COPD within a time window of 24 to 12 months before the most recent date when data were extracted from the GP practice (to select all patients with active COPD with at least one-year of follow-up after ID)
The study will describe demographics, comorbidities and clinical characteristics of the four cohorts and the subpopulations in the baseline year prior to ID and describe outcomes and mortality in a year after ID.
Outcomes of HCRU will be measured in one year after ID (outcome year) for those from cohorts 1-3 who have
complete data and will also be described in the year prior to ID (baseline year) (objective 3) as mean numbers of:
1. COPD exacerbations (acute oral corticosteroids and/or respiratory-related antibiotics course and/or respiratory-related A&E attendance or inpatient hospitalisation)
2. Inpatient hospitalisation admissions (numbers, duration and readmissions within 30, 60 and 90 days) for:
a. COPD exacerbation (ICD10 J44.0, J44.1 or J44.9)
b. COPD (J40.0-J44.9)
c. Respiratory related disease (J%)
d. All-cause
3. Accident & Emergency (A&E) attendances for
a. COPD (DIAG2 = 25 or DIAG = 'COPD' or DIAG2 = 'J4')
b. All-cause
4. Outpatient visits,
a. Respiratory disease (Service code 340)
b. All-cause
The mortality rate will be described in all patients from cohorts 1-3 using linked ONS data:
a. COPD-related (J40.0-J44.9)
b. All-cause
David Price - Chief Investigator - OPRI - Observational and Pragmatic Research Institute Pte Ltd
Marjan Kerkhof - Corresponding Applicant - OPRI - Observational and Pragmatic Research Institute Pte Ltd
Derek Skinner - Collaborator - Research in Real Life ltd.( RiRl )
Marianna Alacqua - Collaborator - Astra Zeneca Inc - USA
Stephanie Chen - Collaborator - Astra Zeneca Inc - USA
HES Accident and Emergency;HES Admitted Patient Care;HES Outpatient;ONS Death Registration Data