title: Comparison of impulse osillometry system and spirometry for diagnosis of obstructive lung disorders.
abstract: BACKGROUND
  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.
  
  
  METHODS
  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.
  
  
  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.
  
  
  CONCLUSIONS
  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.
authors.affiliation: Department of Pulmonary Medicine, Isfahan University of Medical Sciences, ISFAHAN-IRAN.
authors.forename: Mehdi
authors.initials: M
authors.lastname: Nikkhah
authors.affiliation: Department of Pulmonary Medicine, Isfahan University of Medical Sciences, ISFAHAN-IRAN.
authors.forename: Babak
authors.initials: B
authors.lastname: Amra
authors.affiliation: Department of Pulmonary Medicine, Isfahan University of Medical Sciences, ISFAHAN-IRAN.
authors.forename: Afrooz
authors.initials: A
authors.lastname: Eshaghian
authors.affiliation: Department of Pulmonary Medicine, Isfahan University of Medical Sciences, ISFAHAN-IRAN.
authors.forename: Shahriar
authors.initials: S
authors.lastname: Fardad
authors.affiliation: Department of Pulmonary Medicine, Isfahan University of Medical Sciences, ISFAHAN-IRAN.
authors.forename: Assadolah
authors.initials: A
authors.lastname: Asadian
authors.affiliation: Department of Pulmonary Medicine, Isfahan University of Medical Sciences, ISFAHAN-IRAN.
authors.forename: Tooraj
authors.initials: T
authors.lastname: Roshanzamir
authors.affiliation: Department of Pulmonary Medicine, Isfahan University of Medical Sciences, ISFAHAN-IRAN.
authors.forename: Mojtaba
authors.initials: M
authors.lastname: Akbari
authors.affiliation: Bamdad Respiratory and Sleep Research Center, ISFAHAN-IRAN.
authors.forename: Mohammad
authors.initials: M
authors.lastname: Golshan
keywords: Asthma; COPD; Impulse Osillometry System (IOS); Spirometry