Chronic Obstructive Pulmonary Disease (COPD) is a lung disease characterized by increasing breathlessness that worsens over time. COPD is a major cause of disability and has become the third cause of death globally. Treatments attempt to prevent or delay acute exacerbations of COPD that contribute to worsen the disease over time. Acute exacerbations are characterized by a sudden increase in wheezing, shortness of breath, as well as presence of persistent cough, and can require hospitalisation when severe. There is no cure and treatments revolve around symptom relief and controlling the inflammation from the disease. The current treatments, bronchodilators and inhaled corticosteroids, have been available for a long time with no new effective treatments. A large proportion of patients with COPD also have cardiovascular disease (CVD), such as myocardial infarction, stroke, or heart failure, etc. Both diseases share common risk factors such as smoking, increased age and decreased physical activity. Aspirin is an old drugs that has been shown to be effective for cardiovascular disease and has recently been suggested as potentially improving outcomes in patients with COPD. Our study will investigate the effectiveness of aspirin use on reducing the incidence of COPD exacerbations and death. Since aspirin inhibits platelet activity, we will also investigate the role that platelets play in the incidence of COPD exacerbations. This study will inform new and more valid clinical recommendations on how to improve major outcomes for COPD patients worldwide.
The objective of this study is to evaluate the effectiveness of aspirin use on reducing the incidence of COPD exacerbations and mortality in patients with COPD. We will use the Clinical Practice Research Datalink (CPRD) to form a base cohort of patients with a COPD diagnosis, aged 55 or over, and treated with long-acting bronchodilators. We will use a prevalent new-user design to design the study cohort, whereby for each patient who initiates aspirin during follow-up, a time-conditional propensity score-matched reference subject unexposed to aspiring will be selected from the corresponding exposure set of patients with same time since cohort entry and with a visit to a physician at the time of the exposure set. Thus, the time span between base cohort entry and study cohort entry is inherently a matching covariate. The propensity scores will use a high-dimensional propensity score (HDPS) technique by identifying all available data (e.g., diagnoses, procedures, medications) in the one-year period prior to the date of the matched set and applying conditional logistic regression to estimate the time-conditional propensity score. The matched subjects in the study cohort will be followed for one year from cohort entry, date of death, June 2020, or the end of coverage in the practice, whichever is first. The primary outcome is the first moderate or severe COPD exacerbation to occur after cohort entry, defined as a new prescription for prednisolone during follow-up or hospitalization for COPD as primary cause. A secondary outcome is all-cause mortality. The comparative analysis of time to the first exacerbation and time to death within one year will use a Cox proportional hazard regression model to perform an as-treated analysis to estimate the hazard ratio of COPD exacerbation and mortality with current use of aspirin, also according to platelet counts.
Moderate or severe COPD exacerbations; All-cause mortality;
Samy Suissa - Chief Investigator - Sir Mortimer B Davis Jewish General Hospital
Samy Suissa - Corresponding Applicant - Sir Mortimer B Davis Jewish General Hospital
Anirudh Bakshi - Collaborator - McGill University
Pierre Ernst - Collaborator - McGill University
Sophie Dell'Aniello - Collaborator - McGill University
HES Admitted Patient Care