Machine learning-derived asthma phenotypes in a representative Swedish
adult population
Abstract
Background Asthma is a heterogenous airway disease
characterized by multiple phenotypes. Unbiased identification of these
phenotypes is paramount for optimizing asthma management.
Objectives To identify and characterize asthma phenotypes based
on a broad set of attributes using a novel machine learning approach in
a representative sample of Swedish adults. Methods Deep
learning clustering was used to derive asthma phenotypes in a sample of
1,895 subjects aged 16-75, drawn from the ongoing West Sweden Asthma
Study. The algorithm integrated 47 variables encompassing demographics,
risk factors, asthma triggers, pulmonary function, disease severity,
allergy, and comorbidity profiles. The optimal clustering solution was
selected by combining statistical metrics and clinical interpretation.
Results A four-cluster solution was determined to reliably
represent the data, resulting in distinct phenotypes described as: (1)
troublesome, late-onset, non-atopic asthma with smoking ( n=458,
24.2%); 2) female-dominated early adult-onset asthma ( n=545,
28.7%); 3) adult-onset asthma with high inflammation ( n=358,
18.9%); and 4) early-onset, mild, atopic asthma ( n=534,
28.2%). The phenotypes also differed with respect to demographics, risk
factors, asthma triggers, pulmonary function, symptom profiles, and
markers of inflammation. Current asthma was more common in phenotypes
with later age of asthma onset than phenotypes with early onset.
Conclusion Four clinically meaningful asthma phenotypes,
distinguishable by age of onset, severity, risk factors, and prognosis,
were found in Swedish adults. This provides a setting for future
research to profile the immunological basis of the phenotypes, and
further our understanding of their pathophysiology, therapeutic
possibilities, future clinical outcomes, and societal burden.