Related Experiment Video
Updated: Apr 20, 2026

Methodology for Sputum Induction and Laboratory Processing
Published on: December 17, 2017
Classification and implementation of asthma phenotypes in elderly patients.
Heung-Woo Park1, Woo-Jung Song1, Sae-Hoon Kim2
1Department of Internal Medicine, Seoul National University College of Medicine, Seoul, Korea; Institute of Allergy and Clinical Immunology, Seoul National University Medical Research Center, Seoul, Korea.
Researchers identified four distinct asthma phenotypes in elderly patients using cluster analysis. A simple decision-tree algorithm aids in identifying patients prone to acute asthma exacerbations.
Area of Science:
- Geriatric Medicine
- Pulmonology
- Data Science in Healthcare
Background:
- Asthma management in the elderly requires clear phenotypic classification, which is currently lacking.
- Optimal treatment strategies for elderly asthma patients depend on precise phenotype identification.
Purpose of the Study:
- To classify elderly asthma patients (≥ 65 years) into distinct phenotypes using cluster analysis.
- To develop a practical decision-tree algorithm for implementing these asthma classifications.
Main Methods:
- K-means cluster analysis was applied to a cohort of 872 elderly asthma patients.
- Acute asthma exacerbation data over 2 years were used to evaluate clinical trajectories.
- A decision-tree algorithm was developed and validated using a secondary cohort.
Main Results:
- Four distinct elderly asthma clusters were identified: (1) long symptoms/airway obstruction, (2) female/normal lung function, (3) male smokers/reduced lung function, (4) high BMI/borderline lung function.
- Cluster grouping significantly predicted time to first acute asthma exacerbation (P = .01).
- The decision-tree algorithm, using predicted FEV1 and smoking pack-years, demonstrated efficient classification.
Conclusions:
- Four elderly asthma phenotypic clusters with varying exacerbation risks were defined.
- A simplified decision-tree algorithm facilitates practical application for understanding elderly asthma.
- This approach helps identify elderly patients at higher risk for asthma exacerbations.
Related Concept Videos
Asthma-II: Pathophysiology and Classification
Additionally, environmental and genetic factors play crucial roles in determining an individual's susceptibility to asthma and the severity of their condition.
Critical processes in asthma pathophysiology include:
Asthma-III: Symptoms and Complications
Classification of Asthma
Asthma III: Clinical Manifestations
Asthma I: Introduction
Asthma-IV: Diagnostic and Management
Clinical Assessment for Asthma:
This is the first step in diagnosing and managing asthma. It includes:
Asthma: Pathogenesis and Management
Asthma is classified as allergic and non-allergic. Allergens such as dust mites, pollen, and pet dander trigger allergic asthma, while factors like cold air, intense emotions, or exercise can induce non-allergic asthma.

