COPD diagnosis: moving towards a multidimensional approach

2026: ERS satellite online

Andningsvägar Forskning inom området KOL

DELA MED SIG

Fixed ratio spirometry has its limitations in diagnosing COPD

The session challenged one of the most fundamental dogmas in respiratory medicine: that spirometry with post-bronchodilator FEV₁/FVC<0.70 is mandatory to establish the diagnosis of COPD. This is a practical and standardised definition, included in GOLD recommendations,² but carries important limitations including under-diagnosis in patients with clinical expressions of disease.

Nicolai Krogh
Medical Advisor, Chiesi Nordic

For decades, COPD diagnosis has relied on post-bronchodilator spirometry, using a fixed ratio threshold (FEV₁/FVC <0.70 or < LLN). This definition carries important limitations:

• Underdiagnosis in younger individuals
• Overdiagnosis in older adults
• Failure to capture early structural or functional abnormalities
• Poor reflection of disease heterogeneity

Epidemiological data increasingly demonstrate that people with respiratory symptoms or imaging abnormalities may not meet the fixed ratio threshold – yet still experience exacerbations, accelerated lung-function decline, and increased mortality risk.^3-5 Conversely, some individuals meeting the spirometric threshold may have limited clinical expression of disease.¹

A Multidimensional Diagnostic Approach

Bhatt and colleagues proposes moving from a single physiological threshold toward a multidimensional diagnostic framework.¹

The multidimensional schema integrates airflow obstruction (FEV₁/FVC <0.70 or < LLN) with five minor criteria:

• CT emphysema
• CT bronchial wall thickening
• dyspnea (mMRC  ≥2)
• impaired respiratory health status (SGRQ ≥25  or CAT ≥10)
• chronic bronchitis.

This allows for identification of individuals with clinically and structurally relevant disease features who are missed by spirometry alone.¹ The aim is not to abandon spirometry, but to contextualise it within a broader, biologically informed model of disease.

This shift reflects a growing understanding that COPD begins years before overt airflow obstruction becomes detectable by conventional criteria. Studies have demonstrated that CT abnormalities, including narrowing and disappearance of small airways and accelerated FEV₁ decline, may precede spirometric obstruction.⁶

Why This Matters Clinically

A multidimensional diagnostic approach may improve risk stratification and reduce misclassification compared with spirometry alone, identifying individuals without airflow obstruction who nevertheless have elevated risks of mortality, exacerbations, and lung function decline. By integrating clinical, physiologic, and imaging features, the framework aligns diagnosis more closely with disease burden and prognostic risk rather than relying solely on a fixed spirometric threshold.

At the same time, questions remain regarding implementation in routine practice, the feasibility of incorporating CT imaging more broadly, how to balance over- and underdiagnosis, and the potential health-economic implications.

Key takeaway: think beyond FEV₁/FVC <0.70

The key takeaway from this ERS Satellite session was clear: COPD diagnosis is evolving from a single-number definition to a biologically and clinically integrated construct. As evidence accumulates, clinicians may need to think beyond FEV₁/FVC <0.70 and adopt a more nuanced approach that better reflects real-world disease presentation and progression.

Nicolai Krogh
Medical Advisor, Chiesi Nordic

ID 20190-11.03.2026