Fast Decliner Phenotype of Chronic Obstructive Pulmonary Disease (COPD): Applying Machine Learning for Predicting Lung Function Loss

Background: Chronic Obstructive Pulmonary Disease (COPD) is a heterogeneous group of lung conditions challenging to diagnose and treat. Identification of phenotypes of patients with lung function loss may allow early intervention and improve disease management. We characterized patients with the “fast decliner” phenotype, determined its reproducibility, and predicted lung function decline after COPD diagnosis.
Methods: A prospective 4-years observational study that applies machine learning tools to identify COPD phenotypes among 13260 patients from the UK Royal College of General Practitioners and Surveillance Centre database. The phenotypes were identified prior to diagnosis (training dataset), and their reproducibility was assessed after COPD diagnosis (validation dataset).
Results: Three COPD phenotypes were identified, the most common of which was the “fast decliner” - characterized by patients of younger age with the lowest number of COPD exacerbations and better lung function - yet a fast decline in lung function with increasing number of exacerbations. The other two phenotypes were characterized by a) patients with the highest prevalence of COPD severity and b) patients of older age, most males and the highest prevalence of diabetes, cardiovascular comorbidities, and hypertension. These
phenotypes were reproduced in the validation dataset with 80% accuracy. Gender, COPD severity, and exacerbations were the most important risk factors for lung function decline in the most common phenotype.

Conclusions: In this study, three COPD phenotypes were identified prior to patients being diagnosed with COPD. The reproducibility of those phenotypes in a blind dataset following COPD diagnosis suggests their generalizability among different populations.