title: Detection of exacerbations in asthma based on electronic diary data: results from the 1-year prospective BIOAIR study.
abstract: BACKGROUND
  Objective measures are required that may be used as a proxy for exacerbations in asthma. The aim was to determine the sensitivity and specificity of electronic diary data to detect severe exacerbations (SEs) of asthma. A secondary aim was to identify phenotypic variables associated with a higher risk of exacerbation.
  
  
  METHODS
  In the BIOAIR study, 169 patients with asthma (93 severe (SA); 76 mild to moderate (MA)) recorded lung function, symptoms and medication use in electronic diaries for 1 year. Data were analysed using receiver-operator characteristics curves and related to physician-diagnosed exacerbations. Medical history and baseline clinical data were used to assess risk of exacerbation.
  
  
  RESULTS
  Of 122 physician-diagnosed exacerbations, 104 occurred in the SA group (1.1 per patient/year), 18 in the MA group (0.2 per patient/year) and 63 were severe using American Thoracic Society/European Respiratory Society criteria. During exacerbations, peak expiratory flow (PEF) and forced expiratory volume in 1 s significantly decreased, whereas day and night symptoms significantly increased. An algorithm combining a 20% decrease in PEF or a 20% increase in day symptoms on 2 consecutive days was able to detect SEs with 65% sensitivity and 95% specificity. The strongest risk factors for SEs were low Asthma Control Questionnaire score, sputum eosinophils ≥ 3%, body mass index >25 and low quality of life (St George's Respiratory Questionnaire), with ORs between 3.61 and 2.22 (p<0.05).
  
  
  CONCLUSIONS
  Regular electronic monitoring of PEF and asthma symptoms provides an acceptable sensitivity and specificity for the detection of SEs and may be suitable for personal internet-based monitoring of asthma control.
authors.affiliation: Centre for Allergy Research, Karolinska Institutet, , Stockholm, Sweden.
authors.forename: Maciej
authors.initials: M
authors.lastname: Kupczyk
authors.forename: Shushila
authors.initials: S
authors.lastname: Haque
authors.forename: Peter J
authors.initials: PJ
authors.lastname: Sterk
authors.forename: Ewa
authors.initials: E
authors.lastname: Niżankowska-Mogilnicka
authors.forename: Alberto
authors.initials: A
authors.lastname: Papi
authors.forename: Elisabeth H
authors.initials: EH
authors.lastname: Bel
authors.forename: Pascal
authors.initials: P
authors.lastname: Chanez
authors.forename: Barbro
authors.initials: B
authors.lastname: Dahlén
authors.forename: Mina
authors.initials: M
authors.lastname: Gaga
authors.forename: Mark
authors.initials: M
authors.lastname: Gjomarkaj
authors.forename: Peter H
authors.initials: PH
authors.lastname: Howarth
authors.forename: Sebastian L
authors.initials: SL
authors.lastname: Johnston
authors.forename: Guy F
authors.initials: GF
authors.lastname: Joos
authors.forename: Frank
authors.initials: F
authors.lastname: Kanniess
authors.forename: Eleni
authors.initials: E
authors.lastname: Tzortzaki
authors.forename: Anna
authors.initials: A
authors.lastname: James
authors.forename: Roelinde J M
authors.initials: RJ
authors.lastname: Middelveld
authors.forename: Sven-Erik
authors.initials: SE
authors.lastname: Dahlén
mesh_terms: D000280:Administration, Inhalation; D000293:Adolescent; D000328:Adult; D000368:Aged; D001249:Asthma / Q000175:diagnosis* / Q000188:drug therapy / Q000503:physiopathology; D001993:Bronchodilator Agents / Q000008:administration & dosage / Q000627:therapeutic use; D019819:Budesonide / Q000008:administration & dosage / Q000627:therapeutic use*; D018592:Cross-Over Studies; D018450:Disease Progression; D004359:Drug Therapy, Combination; D057286:Electronic Health Records / Q000706:statistics & numerical data*; D005260:Female; D005500:Follow-Up Studies; D005541:Forced Expiratory Volume; D005938:Glucocorticoids / Q000627:therapeutic use; D006801:Humans; D008297:Male; D008875:Middle Aged; D010366:Peak Expiratory Flow Rate; D011379:Prognosis; D011446:Prospective Studies; D011788:Quality of Life; D012680:Sensitivity and Specificity; D011795:Surveys and Questionnaires; D013997:Time Factors; D055815:Young Adult
chemical_list: D001993:Bronchodilator Agents; D005938:Glucocorticoids; D019819:Budesonide
keywords: Asthma; Asthma Guidelines; Respiratory Measurement