PIF/PEF Ratio: A Novel Marker for COPD Severity

<bold>Introduction:</bold> Peak Expiratory Flow (PEF) and Peak Inspiratory Flow (PIF) are commonly used to assess lung function in patients with COPD. However, few studies have examined the role of the PIF/PEF ratio in these patients. <bold>Objective:</bold> To assess the correlation of the PIF/PEF ratio with bronchial obstruction, quality of life and frequency of exacerbations in patients with COPD. <bold>Materials and methods:</bold> This was a cross-sectional study including 58 COPD patients referred to Pulmonary Function Testing Department at Abderrahmane Mami Hospital, Ariana. All patients underwent spirometry to measure Forced Expiratory Volume in the first second (FEV1), Forced Vital Capacity (FVC), PIF and PEF. Quality of life was assessed using the CAT questionnaire, and the frequency of exacerbations over the past year was recorded. <bold>Results:</bold> The mean age was 63.45±6.99 years. Mean FVC% and FEV1% were 78.14±21.62 and 51.53±17.87 respectively. Among our patients, 38.6% were frequent exacerbators (≥2 exacerbations). The PIF/PEF ratio was correlated with the FEV1/CVF ratio (r = -0.41; p < 0.0001), FEV1 (r = -0.51; p < 0.0001) and frequency of exacerbations (r=0.45; p<0.0001). However, no significant correlation was found between the PIF/PEF ratio and the CAT score. <bold>Conclusion:</bold> The PIF/PEF ratio could be used as a spirometric marker of severity in COPD patients.