title: Logistic regression model for prediction of airway reversibility using peak expiratory flow.
abstract: BACKGROUND
  Using peak expiratory flow (PEF) as an alternative to spirometry parameters (FEV1 and FVC), for detection of airway reversibility in diseases with airflow limitation is challenging. We developed logistic regression (LR) model to discriminate bronchodilator responsiveness (BDR) and then compared the results of models with a performance of >18%, >20%, and >22% increase in ΔPEF% (PEF change relative to baseline), as a predictor for bronchodilator responsiveness (BDR).
  
  
  METHODS
  PEF measurements of pre-bronchodilator, post-bronchodilator and ΔPEF% of 90 patients with asthma (44) and chronic obstructive pulmonary disease (46) were used as inputs of model and the output was presence or absence of the BDR.
  
  
  RESULTS
  Although ΔPEF% was a poor discriminator, LR model could improve the accuracy of BDR. Sensitivity, specificity, positive predictive value, and negative predictive value of LR were 68.89%, 67.27%, 71.43%, and 78.72%, respectively.
  
  
  CONCLUSIONS
  The LR is a reliable method that can be used clinically to predict BDR based on PEF measurements.
authors.affiliation: Department of Pulmonary Medicine, Shariati Hospital, Tehran University of Medical Sciences, Tehran, Iran.
authors.forename: Javad
authors.initials: J
authors.lastname: Shakeri
authors.affiliation: Department of Pulmonary Medicine, Shariati Hospital, Tehran University of Medical Sciences, Tehran, Iran.
authors.forename: Omalbanin
authors.initials: O
authors.lastname: Paknejad
authors.affiliation: Department of Pulmonary Medicine, Shariati Hospital, Tehran University of Medical Sciences, Tehran, Iran.
authors.forename: Keivan Gohari
authors.initials: KG
authors.lastname: Moghadam
authors.affiliation: Department of Pulmonary Medicine, Shariati Hospital, Tehran University of Medical Sciences, Tehran, Iran.
authors.forename: Maryam
authors.initials: M
authors.lastname: Taherzadeh
keywords: Airway reversibility; Logistic regression; Peak expiratory flow; Spirometry