title: Development and validation of a novel risk score for asthma exacerbations: The risk score for exacerbations.
abstract: BACKGROUND
  Identifying patients at risk of future severe asthma exacerbations, those whose asthma might be less treatment responsive, or both might guide treatment selection.
  
  
  OBJECTIVE
  We sought to investigate predictors for failure to achieve Global Initiative for Asthma (GINA)-defined good current asthma control and severe exacerbations on treatment and to develop a simple risk score for exacerbations (RSE) for clinical use.
  
  
  METHODS
  A large data set from 3 studies comparing budesonide/formoterol maintenance and reliever therapy with fixed-dose inhaled corticosteroid/long-acting β2-agonist therapy was analyzed. Baseline patient characteristics were investigated to determine dominant predictors for uncontrolled asthma at 3 months and for severe asthma exacerbations within 12 months of commencing treatment. The RSE, right censored at 6 months to include all 3 studies, was based on the dominant predictors for exacerbations in two thirds of the data set and validated in one third.
  
  
  RESULTS
  Patients (n = 7446) whose symptoms were not controlled on GINA treatment steps 3 and 4 and with 1 or more exacerbations (as judged by a clinician based on patient records, history, or both) in the previous year were included. On multivariate analysis, GINA step, reliever use, postbronchodilator FEV1, and 5-item Asthma Control Questionnaire score were dominant (all P < .001) predictors for both the risk of uncontrolled asthma and severe exacerbations. Additional dominant predictors for uncontrolled asthma were smoking status and asthma symptom scores and an additional predictor for severe exacerbation was body mass index. An exponential increase in risk was observed with increments in RSE based on 5 selected predictors for exacerbations.
  
  
  CONCLUSIONS
  Risk of uncontrolled asthma at 3 months and a severe exacerbation within 12 months can be estimated from simple clinical assessments. Prospective validation of these predictive factors and the RSE is required. Use of these models might guide the management of asthmatic patients.
authors.affiliation: Division of Pulmonology, Department of Medicine, University of Cape Town, Cape Town, South Africa. Electronic address: Eric.Bateman@uct.ac.za.
authors.forename: Eric D
authors.initials: ED
authors.lastname: Bateman
authors.affiliation: Pulmonary Department, Mainz University Hospital, Mainz, Germany.
authors.forename: Roland
authors.initials: R
authors.lastname: Buhl
authors.affiliation: Michael G DeGroote School of Medicine, Faculty of Health Sciences, McMaster University, Hamilton, Ontario, Canada.
authors.forename: Paul M
authors.initials: PM
authors.lastname: O'Byrne
authors.affiliation: Université Paris-Sud 11, Service de Pneumologie et Réanimation Respiratoire, Hôpital Antoine Béclère, APHP, Clamart, France.
authors.forename: Marc
authors.initials: M
authors.lastname: Humbert
authors.affiliation: Clinical Management Group, Woolcock Institute of Medical Research, University of Sydney, Sydney, Australia.
authors.forename: Helen K
authors.initials: HK
authors.lastname: Reddel
authors.affiliation: Michael G DeGroote School of Medicine, Faculty of Health Sciences, McMaster University, Hamilton, Ontario, Canada.
authors.forename: Malcolm R
authors.initials: MR
authors.lastname: Sears
authors.affiliation: Respiratory Group, The George Institute for Global Health, Sydney, Australia.
authors.forename: Christine
authors.initials: C
authors.lastname: Jenkins
authors.affiliation: Respiratory Research Unit, City Hospital Campus, Nottingham University, Nottingham, United Kingdom.
authors.forename: Tim W
authors.initials: TW
authors.lastname: Harrison
authors.affiliation: Department of Allergy, Hospital La Paz Institute for Health Research (IdiPAZ), Madrid, Spain.
authors.forename: Santiago
authors.initials: S
authors.lastname: Quirce
authors.affiliation: StatMind AB, Lund, Sweden.
authors.forename: Stefan
authors.initials: S
authors.lastname: Peterson
authors.affiliation: Department of Respiratory Medicine and Allergology, University Hospital, Lund, Sweden.
authors.forename: Göran
authors.initials: G
authors.lastname: Eriksson
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D018927:Anti-Asthmatic Agents / Q000627:therapeutic use*; D001249:Asthma / Q000175:diagnosis* / Q000188:drug therapy* / Q000503:physiopathology; D015992:Body Mass Index; D019819:Budesonide / Q000627:therapeutic use*; D002648:Child; D018450:Disease Progression; D004983:Ethanolamines / Q000627:therapeutic use*; D005260:Female; D005541:Forced Expiratory Volume; D000068759:Formoterol Fumarate; D006801:Humans; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D016032:Randomized Controlled Trials as Topic; D012107:Research Design; D012189:Retrospective Studies; D018570:Risk Assessment / Q000706:statistics & numerical data*; D012307:Risk Factors; D012720:Severity of Illness Index; D012907:Smoking / Q000503:physiopathology; D011795:Surveys and Questionnaires
chemical_list: D018927:Anti-Asthmatic Agents; D004983:Ethanolamines; D019819:Budesonide; D000068759:Formoterol Fumarate
keywords: Asthma; Global Initiative for Asthma; asthma control; budesonide/formoterol maintenance and reliever therapy; exacerbations; predictors; risk score