Öz
Forced expiratory flow (FEF25-75%) between 25%-75% of vital capacity is the pulmonary function test (PFT) parameter used in the evaluation of small airway disease (SAD).In our study, we aimed to emphasize the reasons for the admission of patients with a low FEF25-75% who applied to the pulmonary diseases polyclinic, the contribution of FEF25-75% to the early diagnosis of chronic obstructive pulmonary disease (COPD), and the importance of early intervention for risk factors. The study included 381 patients with acceptable PFT who applied to the ESOGU pulmonary diseases polyclinic between January 2020 and April 2021.ShapiroWilk, Mann-Whitney U and Chi-square tests were used for statistical analysis. p<0.05 was considered statistically significant. The mean age of 381 patients (184 females and 197 males) included in the study was 56.90±14.09 years (range 20-88 years).The reasons for applying to the polyclinic were defined in 4 groups as 'control application', 'first application', 'health report' and 'preoperative evaluation', and SAD was defined as FEF25-75%<65. A significant correlation was found between advanced age (≥50 years), smoking, history of comorbid disease, and symptoms of dyspnea and SAD (p<0.05).There was no difference between the groups in terms of gender, BMI and previous lung disease (p>0.05). A statistically significant correlation was observed between smoking, comorbid disease, previous disease history, and admission symptoms and reasons for admission (p<0.05). FEF25-75% was significantly lower in smoking men compared to women (p=0.022). SAD was higher in men smokers than in women, while advanced age, smoking, history of comorbid disease and symptoms of dyspnea were significantly associated with SAD.Consideration of these factors by clinicians is important for the evaluation of FEF 25-75%, which guides both the early diagnosis of obstructive diseases and the course and treatment of the disease, and the development of targeted therapies.