title: Peak expiratory flow as a screening tool to detect airflow obstruction in a primary health care setting.
abstract: BACKGROUND
  Peak expiratory flow (PEF) measurement is less expensive and requires fewer skills than spirometry testing. It is thus expected to be a reasonable substitute for spirometry in airflow obstruction screening when spirometry is unavailable.
  
  
  OBJECTIVE
  To evaluate the validation  of PEF measurement in the detection of airflow obstruction using newly established regression equations.
  
  
  METHODS
  The PEFs of 553 'normal' participants aged 40-85 years were measured using mechanical devices. Based on these data, regression equations were generated to  predict normal PEF values. Data were then collected from 3379 subjects. The specificity and sensitivity of the different predicted PEF cut-off points for detecting airflow obstruction were evaluated by spirometry, based on previously generated regression equations.
  
  
  RESULTS
  Using newly  established reference values for PEF, PEF had higher sensitivity and specificity than the questionnaire in detection of airflow obstruction. That PEF < 80% of predicted was more effective in the detection of airflow obstruction was confirmed by the lower limit of normal of forced expiratory  volume in 1 second/forced vital capacity, Global Initiative for Chronic Obstructive Lung Disease (GOLD), and GOLD plus symptom, with a sensitivity of 78.7%, 76.8%, 85.3% and a specificity of 81.9%, 83.8%, 81.4%, respectively.
  
  
  CONCLUSIONS
  Mechanical PEF may be a reasonable method of screening  for airflow obstruction in settings where spirometry is unavailable.
authors.affiliation: State Key Laboratory of Respiratory Disease, Guangzhou Institute of Respiratory Diseases, The First Affiliated Hospital, Guangzhou Medical University, Guangzhou, Guangdong, China.
authors.forename: J
authors.initials: J
authors.lastname: Tian
authors.forename: Y
authors.initials: Y
authors.lastname: Zhou
authors.forename: J
authors.initials: J
authors.lastname: Cui
authors.forename: D
authors.initials: D
authors.lastname: Wang
authors.forename: X
authors.initials: X
authors.lastname: Wang
authors.forename: G
authors.initials: G
authors.lastname: Hu
authors.forename: Y
authors.initials: Y
authors.lastname: Tian
authors.forename: Y
authors.initials: Y
authors.lastname: Jiang
authors.forename: J
authors.initials: J
authors.lastname: Zheng
authors.forename: J
authors.initials: J
authors.lastname: Wang
authors.forename: N
authors.initials: N
authors.lastname: Zhong
authors.forename: P
authors.initials: P
authors.lastname: Ran
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000402:Airway Obstruction / Q000175:diagnosis* / Q000473:pathology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010366:Peak Expiratory Flow Rate; D011237:Predictive Value of Tests; D011320:Primary Health Care / Q000379:methods*; D012016:Reference Values; D012044:Regression Analysis; D012680:Sensitivity and Specificity; D013147:Spirometry / Q000379:methods; D011795:Surveys and Questionnaires