title: Reliability and factor analysis of the Spanish version of the asthma control test.
abstract: BACKGROUND
  The Asthma Control Test (ACT) has been developed to evaluate asthma control and to reflect its nature. A Spanish version of the test has been widely disseminated to physicians, but it has not yet been validated.
  
  
  OBJECTIVE
  To examine the psychometric properties of the Spanish version of the ACT.
  
  
  METHODS
  A total of 322 asthmatic patients with a mean (SD) age of 43.8 (17.3) years (range, 12-84 years) with appropriate criteria for inclusion completed the ACT. Spirometric variables were measured and asthma severity was rated by physicians.
  
  
  RESULTS
  Internal consistency reliability was 0.79. The ACT showed weak correlation coefficients with forced expiratory volume in 1 second (FEV1) (p = 0.27; P = .01) and asthma severity (p = -0.19; P = .01). Almost 40% of patients with an FEV1 less than 60% of predicted rated their asthma as well or totally controlled; conversely, 70% of patients with asthma well or totally controlled showed an FEV1 less than 80% of predicted. The factor analysis revealed a 2-factor solution: the first component included the 5 items of the ACT (subjective component), and the second component included the spirometric measures (objective component). The 2-factor solution accounted for 66.2% of the total variance.
  
  
  CONCLUSIONS
  These data reveal a unidimensional structure of the ACT and do not support the use of this test without spirometry in the management of asthma. Spirometry provides important complementary information about asthma severity that may be used in conjunction with clinical assessments of controlto provide optimal management in many patients.
authors.affiliation: Departamento de Emergencia, Hospital Central de las Fuerzas Armadas, Montevideo, Uruguay. gurodrig@adinet.com.uy
authors.forename: Gustavo J
authors.initials: GJ
authors.lastname: Rodrigo
authors.forename: José Pedro
authors.initials: JP
authors.lastname: Arcos
authors.forename: Luís J
authors.initials: LJ
authors.lastname: Nannini
authors.forename: Hugo
authors.initials: H
authors.lastname: Neffen
authors.forename: Marisa González
authors.initials: MG
authors.lastname: Broin
authors.forename: Mariela
authors.initials: M
authors.lastname: Contrera
authors.forename: Luís
authors.initials: L
authors.lastname: Piñeyro
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001118:Argentina; D001249:Asthma / Q000175:diagnosis* / Q000503:physiopathology*; D002648:Child; D005163:Factor Analysis, Statistical; D005260:Female; D005541:Forced Expiratory Volume / Q000502:physiology; D006801:Humans; D007802:Language; D008297:Male; D008875:Middle Aged; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012737:Sex Factors; D013147:Spirometry; D011795:Surveys and Questionnaires; D014583:Uruguay; D014797:Vital Capacity / Q000502:physiology