title: Forced oscillation technique in the detection of smoking-induced respiratory alterations: diagnostic accuracy and comparison with spirometry.
abstract: BACKGROUND
  Detection of smoking effects is of utmost importance in the prevention of cigarette-induced chronic airway obstruction. The forced oscillation technique offers a simple and detailed approach to investigate the mechanical properties of the respiratory system. However, there have been no data concerning the use of the forced oscillation technique to evaluate respiratory mechanics in groups with different degrees of tobacco consumption.
  
  
  OBJECTIVE
  (1) to evaluate the ability of the forced oscillation technique to detect smoking-induced respiratory alterations, with special emphasis on early alterations; and (2) to compare the diagnostic accuracy of the forced oscillation technique and spirometric parameters.
  
  
  METHODS
  One hundred and seventy subjects were divided into five groups according to the number of pack-years smoked: four groups of smokers classified as < 20, 20-39, 40-59, and > 60 pack-years and a control group. The four groups of smokers were compared with the control group using receiver operating characteristic (ROC) curves.
  
  
  RESULTS
  The early adverse effects of smoking in the group with < 20 pack-years were adequately detected by forced oscillation technique parameters. In this group, the comparisons of the ROC curves showed significantly better diagnostic accuracy (p < 0.01) for forced oscillation technique parameters. On the other hand, in groups of 20-39, 40-59, and > 60 pack-years, the diagnostic performance of the forced oscillation technique was similar to that observed with spirometry.
  
  
  CONCLUSIONS
  This study revealed that forced oscillation technique parameters were able to detect early smoking-induced respiratory involvement when pathologic changes are still potentially reversible. These findings support the use of the forced oscillation technique as a versatile clinical diagnostic tool in helping with chronic obstructive lung disease prevention, diagnosis, and treatment.
authors.affiliation: Biomedical Instrumentation Laboratory, Institute of Biology, Faculty of Engineering, Universidade do Estado do Rio de Janeiro, Rio de Janeiro, Rio de Janeiro, Brazil.
authors.forename: Alvaro Camilo Dias
authors.initials: AC
authors.lastname: Faria
authors.forename: Alessandra Alves da
authors.initials: AA
authors.lastname: Costa
authors.forename: Agnaldo Jose
authors.initials: AJ
authors.lastname: Lopes
authors.forename: Jose Manoel
authors.initials: JM
authors.lastname: Jansen
authors.forename: Pedro Lopes de
authors.initials: PL
authors.lastname: Melo
mesh_terms: D000403:Airway Resistance / Q000502:physiology*; D016022:Case-Control Studies; D042241:Early Diagnosis; D006801:Humans; D029424:Pulmonary Disease, Chronic Obstructive / Q000175:diagnosis* / Q000209:etiology; D012372:ROC Curve; D012129:Respiratory Function Tests / Q000379:methods / Q000592:standards*; D015656:Respiratory Mechanics / Q000502:physiology*; D012680:Sensitivity and Specificity; D012907:Smoking / Q000009:adverse effects* / Q000503:physiopathology; D013147:Spirometry; D013997:Time Factors