FEF2575 percentage reversibility and its comparison with FEV1 Reversibility in diagnosis of asthma

Background & Objective: Bronchial asthma is a chronic inflammatory disease with reversible airflow obstruction. Smaller airways are primary and most common site of inflammation in bronchial asthma. FEF2575 is a measure of small airway function and may serve as a useful marker in the diagnosis of asthma. Conventional spirometry criteria, particularly bronchodilator reversibility of FEV1, exhibit limited sensitivity, potentially leading to missed diagnoses of asthma. There is a need for more parameters like FEF2575 reversibility to enhance diagnostic accuracy within this population. Our objective weas to evaluate whether inclusion of FEF2575 reversibility improves the diagnostic sensitivity of spirometry in patients clinically suspected of having asthma. Methodology: The study included patients who visited the SGRH pulmonary clinic between March to December, 2022. Patients suspected of asthma as per GINA criteria underwent spirometry with bronchodilator reversibility testing, followed by a one-month therapeutic trial. Only those with symptomatic improvement were classified as Clinically confirmed asthma cases and selected for final analysis. A total of 304 non-asthmatic individuals were included as a control group for comparison. Results: A total of 599 individuals, including 295 probable asthmatics, were included in the study. The mean age of participants was 43.2±17.8 years Clinically confirmed asthmatic patients exhibited significantly higher reversibility across all three parameters—FEV1, FEF2575, and FVC—compared to healthy individuals (p-value <0.05). The sensitivity of FEV1, FEF2575, and FVC was 0.31, 0.59, and 0.29, respectively, with a cut-off percentage reversibility of >12%. Conclusion: Incorporating FEF2575 reversibility alongside standard parameters enhances diagnostic sensitivity and may aid in timely confirmation of asthma, potentially improving clinical outcomes through more accurate diagnosis.