Bronchodilator reversibility, body plethysmographic phenotypes, and mortality in patients with COPD or PRISm

<title>Extract</title> Preserved Ratio Impaired Spirometry (PRISm) is defined by a reduced forced expiratory volume in one second (FEV₁<80% predicted) despite a preserved FEV₁/forced vital capacity (FVC) ratio (≥ 0.70). Prevalence estimates vary (∼5–20%) by definition and population. Although this pattern does not fulfil the criteria for spirometric defined airflow obstruction, PRISm has been increasingly recognized as a distinct and clinically relevant spirometric phenotype, associated with respiratory symptoms, reduced functional capacity, and increased all-cause mortality [1, 2], sometimes even approaching the risk seen in mild-to-moderate chronic obstructive pulmonary disease (COPD) [3]. As PRISm may precede spirometric definded COPD; early recognition could enable timely interventions potentially altering the course of disease and preventing progression [2, 4, 5]. So far, two factors have largely been overlooked in PRISm: lung volume measurements and bronchodilator reversibility.