Comparison of impulse osillometry system and spirometry for diagnosis of obstructive lung disorders

Obstructive lung disease is a growing health problem, especially in developed countries. This study aimed to compare Impulse Osillometry System [IOS] and Spirometry for evaluation of Chronic Obstructive Pulmonary Disease and asthma. The study groups contained 87 healthy people, 87 asthmatic patients and 56 COPD patients. Spirometry [FVC, FEV1, FEV1/FVC] and IOS [R5, R20, X5] measurements were performed for all the healthy subjects and patients. The results of IOS were compared with spirometric results. Significant differences were detected among the 3 groups [control, COPD and asthma] in terms of all the spirometric parameters [FVC, FEV1, FEV1/FVC] and some parameters of IOS [R5,R20,X5] measurements [p<0.05]. Among COPD patients, sensitivity for X5 [the best value of IOS measurements in the COPD group] was 76%. Also, in asthmatic patients, sensitivity for R20 [the best value of IOS measurements in the asthma group] was 77%. We found a correlation between R5, R20 and X5 with FEV1 in asthmatic patients, but only R5 had this correlation with FEV1 in COPD patients. We concluded that IOS can be an alternative for spirometry in the diagnosis of obstructive lung disease in patients with minimal cooperation. R5 can represent COPD severity