Background/Rationale: Chronic Obstructive Pulmonary Disease (COPD) is a debilitating condition and one of the most prevalent lung diseases in high income countries, second only to asthma. Patients with COPD can be categorized based on the Global Initiative for Chronic Obstructive Lung Disease (GOLD) system. The pharmacological treatments associated with the different GOLD categories vary. However, the proportions of the patient population within these different categories are unknown, in particular those with more advanced disease using triple therapy.
Objectives:
Primary Objectives
1. To quantify the proportions of patients receiving triple therapy (defined as long-acting beta agonist [LABA], long-acting muscarinic antagonist [LAMA], and inhaled corticosteroid [ICS]) before, at, and after initial COPD diagnosis.
2. To identify pathways to triple therapy among these patients.
3. To calculate the time to initiation of triple therapy from initial diagnosis of COPD.
Secondary Objectives
1. To evaluate the specific factors (e.g., number of exacerbations, symptom score, lung function and phenotype) that influence pathways leading to triple therapy.
2. To identify pathways of step-down from triple therapy.
3. To calculate the time to step-down from triple therapy.
Exploratory Objectives
1. To document dosages of triple therapy.
2. To quantify levels of persistence to specified treatments for COPD.
3. To evaluate the association between discontinuation of specified treatments for COPD and exacerbations
4. To evaluate the association between specified treatments for COPD and utilisation of health care resources
5. To describe changes in therapy for COPD following exacerbation.
6. To describe level of blood eosinophils at various points in time among patients with COPD.
Methods: Investigate the use of triple therapy in a Spanish cohort of COPD patients using retrospective electronic medical records from primary care and pharmacy data.
Study design: Retrospective cohort study.
Data Source: The System for the Development of Research in Primary Care (SIDIAP) is a longitudinal population-based database that has collected information on more than 5.8 million patients from 279 Primary Care Teams in Catalonia, Spain. These data represent 80% of the population of Catalonia and are available from the year 2010 to 2015. The SIDIAP database records patient-level data on symptoms and diagnoses at each visit to a general practitioner (GP), clinical data, prescribed medications, physician visits, and diagnostic/laboratory test results. Individual patient data are not available for release but indirect analysis is possible through the vendor.
Study Population: Patients with COPD related encounter from January 1, 2010 until December 31, 2015. Patients who were < 40 years old on the date of their first ever COPD diagnosis will be excluded from the study. From this pool of patients, additional inclusion/exclusion criteria will be applied to obtain the study cohorts of interest i.e. an incident COPD cohort, incident triple therapy cohort, and prevalent COPD cohort.
Exposure(s): Age, gender, smoking status, relevant comorbidities, COPD phenotype, forced expiratory volume in one second (FEV1), eosinophils, treatments received, healthcare utilization.
Outcome(s): Triple therapy use, step-down from triple therapy, persistence on triple therapy, COPD related exacerbations.
Statistical Analysis: Descriptive statistics will be used to characterize COPD patients and the treatments they receive. More advanced methods will be used to understand time to event outcomes (e.g., time to triple therapy), including Kaplan-Meier analysis and Cox-Regression.