Severity Classification of Functional Impairment Based on ICF Qualifiers: A New Proposal for Assessing Individuals With Pulmonary Hypertension.

Abstract

Background: Pulmonary Hypertension (PH) is a chronic condition that leads to progressive functional limitations, making the assessment of functional capacity essential for clinical management. This study aimed to classify PH patients based on the International Classification of Functioning, Disability, and Health (ICF) qualifiers using the Six-Minute Walk Test (6MWT) and compare this classification with the World Health Organization Functional Classification (WHO-FC).

Methods: This observational study included 33 individuals with PH. Demographic data, pulmonary function, and 6MWT results were collected. Participants were classified according to ICF qualifiers (ranging from no impairment to complete impairment) and WHO-FC. The association between classifications was tested using Fisher's exact test, considering the conceptual differences between them.

Results: Most participants presented moderate functional impairment, with an average 6MWT distance of 431.5 ± 110 m, equivalent to 68% of the predicted value. Based on ICF qualifiers, 39% of patients had mild impairment, 42% moderate, and 18% severe impairment. However, no significant association was found between ICF qualifiers and WHO-FC, reflecting the distinct conceptual frameworks of these classifications. Unlike WHO-FC, which applies fixed cutoffs, the ICF-based classification provides a more individualized assessment by incorporating the contrast between expected and actual performance in the 6MWT.

Discussion: The use of ICF qualifiers enabled a more specific evaluation of functional capacity in PH patients, complementing rather than replacing WHO-FC. This approach allows for a more individualized assessment, supporting targeted rehabilitation strategies and improving clinical decision-making in PH management.