title: Accuracy of FENO for diagnosing asthma: a systematic review.
abstract: Measurement of FENOmight substitute bronchial provocation for diagnosing asthma. We aimed to investigate the diagnostic accuracy of FENOmeasurement compared with established reference standard.
  
  
  
  Systematic review and diagnostic meta-analysis. Data sources were Medline, Embase and Scopus up to 29 November 2015. Sensitivity and specificity were estimated using a bivariate model. Additionally, summary receiver-operating characteristic curves were estimated.
  
  
  
  26 studies with 4518 participants (median 113) were included. Risk of bias was considered low for six of seven items in five studies and for five items in seven studies. The overall sensitivity in the meta-analysis was 0.65 (95% CI 0.58 to 0.72), the overall specificity 0.82 (0.76 to 0.86), the diagnostic OR 9.23 (6.55 to 13.01) and the area under the curve 0.80 (0.77 to 0.85). In meta-regression analyses, higher cut-off values were associated with increasing specificity (OR 1.46 per 10 ppb increase in cut-off) while there was no association with sensitivity. Sensitivities varied significantly within the different FENOdevices, but not specificities. Neither prevalence, age, use of bronchoprovocation in >90% of participants or as exclusive reference standard test, nor risk of bias were significantly associated with diagnostic accuracy.
  
  
  
  There appears to be a fair accuracy of FENOfor making the diagnosis of asthma. The overall specificity was higher than sensitivity, which indicates a higher diagnostic potential for ruling in than for ruling out the diagnosis of asthma.
authors.affiliation: Institute of General Practice, University Hospital Klinikum rechts der Isar, Technische Universität München, Munich, Germany.|Institute of Epidemiology I, Helmholtz Zentrum München-German Research Center for Environmental Health, Munich, Germany.|Institute and Outpatient Clinic for Occupational, Social and Environmental Medicine, Ludwig-Maximilians-Universität, Munich, Germany.
authors.forename: Stefan
authors.initials: S
authors.lastname: Karrasch
authors.affiliation: Institute of General Practice, University Hospital Klinikum rechts der Isar, Technische Universität München, Munich, Germany.
authors.forename: Klaus
authors.initials: K
authors.lastname: Linde
authors.affiliation: Institute for Medical Biometry and Statistics, Medical Center-University of Freiburg, Freiburg, Germany.|Faculty of Medicine, University of Freiburg, Freiburg, Germany.
authors.forename: Gerta
authors.initials: G
authors.lastname: Rücker
authors.affiliation: Institute for Medical Biometry and Statistics, Medical Center-University of Freiburg, Freiburg, Germany.|Faculty of Medicine, University of Freiburg, Freiburg, Germany.
authors.forename: Harriet
authors.initials: H
authors.lastname: Sommer
authors.affiliation: Institute of General Practice, University Hospital Klinikum rechts der Isar, Technische Universität München, Munich, Germany.
authors.forename: Marlies
authors.initials: M
authors.lastname: Karsch-Völk
authors.affiliation: Kleijnen Systematic Reviews Ltd, Escrick, York, UK.|School for Public Health and Primary Care (CAPHRI), Maastricht University, Maastricht, The Netherlands.
authors.forename: Jos
authors.initials: J
authors.lastname: Kleijnen
authors.affiliation: Institute and Outpatient Clinic for Occupational, Social and Environmental Medicine, Ludwig-Maximilians-Universität, Munich, Germany.
authors.forename: Rudolf A
authors.initials: RA
authors.lastname: Jörres
authors.affiliation: Institute of General Practice, University Hospital Klinikum rechts der Isar, Technische Universität München, Munich, Germany.
authors.forename: Antonius
authors.initials: A
authors.lastname: Schneider
mesh_terms: D001249:Asthma / Q000175:diagnosis*; D001944:Breath Tests / Q000379:methods*; D001985:Bronchial Provocation Tests; D003937:Diagnosis, Differential; D005541:Forced Expiratory Volume / Q000502:physiology; D006801:Humans; D009569:Nitric Oxide / Q000032:analysis*
chemical_list: D009569:Nitric Oxide
keywords: Asthma; Exhaled Airway Markers