Evaluation of FEV1/FVC ratio and FEF25-75% among patients performing spirometry in a tertiary care centre: A descriptive cross-sectional study
DOI:
https://doi.org/10.70250/mjpahs229Keywords:
pulmonary function test, small airway obstruction, FEF25-75%Abstract
Introduction: Chronic obstructive pulmonary disease is a major burden, both health and economic burden in developing countries such as Nepal. Though spirometry has been used as essential tool in diagnosing the disease, the early identification of progression of airway obstruction or involvement of small airway obstruction still remains a significant clinical challenge. So, this study therefore aimed to evaluate spirometric parameters, specifically the FEV1/FVC ratio and FEF25–75%, and to explore their clinical implications.”
Methods: Patients who attended the Pulmonary Function Test (PFT) outpatient department at Western Regional Hospital, Pokhara, from September 2025 to December 2025 were enrolled in this study. Ethical approval was obtained from the Institutional Review Committee of Pokhara Academy of Health Sciences. Forced vital capacity (FVC) and related parameters were measured according to American Thoracic Society/European Respiratory Society guidelines, fulfilling both acceptability and repeatability criteria. Spirometric indices were then recorded and analyzed.
Results: Of 370 participants, 149 (40.27%) had a decreased FEV1/FVC ratio and 159 (42.16%) had a decreased FEF25–75%. Both FEV1/FVC and FEF25–75% tended to be lower in older age groups compared with younger age groups (p < 0.001). Among those with a normal FEV1/FVC ratio (≥0.70), 10.50% showed a decreased FEF25–75% (p < 0.001).
Conclusions: The findings indicate that both large and small airway obstruction become more prevalent with increasing age. A decreased FEV1/FVC ratio is usually accompanied by a low FEF25–75%, and a normal FEV1/FVC ratio is usually accompanied by a normal FEF25–75%; however, 10.50% of individuals with a normal FEV1/FVC had a decreased FEF25–75%. A reduced mid expiratory flow (FEF25–75%) despite a preserved FEV1/FVC ratio suggests early or isolated small airways dysfunction.
