title: Validation of a questionnaire (CARAT10) to assess rhinitis and asthma in patients with asthma.
abstract: OBJECTIVE
  The Control of Allergic Rhinitis and Asthma Test (CARAT) was developed to be used in the concurrent management of these diseases, as recommended by the Allergic Rhinitis and its Impact on Asthma (ARIA) guidelines. However, it was necessary to statistically identify and remove redundant questions and to evaluate the new version's factor structure, internal consistency and concurrent validity.
  
  
  METHODS
  In this cross-sectional study 193 adults with allergic rhinitis and asthma from 15 outpatient clinics in Portugal were included. The CARAT questionnaire was reduced using descriptive analysis, exploratory factor analysis and internal consistency. Spearman's correlations were used to compare the CARAT scores with a medical evaluation and other measures of control, including the Asthma Control Questionnaire and symptoms' visual analogue scales. The performance against physician rating of control was summarized using the area under the curve (AUC) from receiver operating characteristic analysis. In addition, CARAT was compared with the physician's decision to reduce, maintain or increase treatment.
  
  
  RESULTS
  The reduced version has 10 questions and 2 factors (CARAT10). The Cronbach's alpha was 0.85. All correlation coefficients of CARAT10 and factors with the different measures of control met the a priori predictions, ranging from 0.58 to 0.79. The AUC was 0.82. For the physician's decision groups of reduce, maintain or increase treatment, the mean (IC95%) scores of CARAT10 were 24 (21.4;26.6), 21 (19.4;21.9) and 15 (13.6;16.5), respectively.
  
  
  CONCLUSIONS
  CARAT10 has high internal consistency and good concurrent validity, making it useful to compare groups in clinical studies.
authors.affiliation: Biostatistics and Medical Informatics Department, Faculdade de Medicina da Universidade do Porto, Porto. jfonseca@med.up.pt
authors.forename: J A
authors.initials: JA
authors.lastname: Fonseca
authors.forename: L
authors.initials: L
authors.lastname: Nogueira-Silva
authors.forename: M
authors.initials: M
authors.lastname: Morais-Almeida
authors.forename: L
authors.initials: L
authors.lastname: Azevedo
authors.forename: A
authors.initials: A
authors.lastname: Sa-Sousa
authors.forename: M
authors.initials: M
authors.lastname: Branco-Ferreira
authors.forename: L
authors.initials: L
authors.lastname: Fernandes
authors.forename: J
authors.initials: J
authors.lastname: Bousquet
mesh_terms: D000328:Adult; D001249:Asthma / Q000150:complications / Q000175:diagnosis / Q000503:physiopathology / Q000628:therapy*; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011174:Portugal; D012221:Rhinitis, Allergic, Perennial / Q000150:complications / Q000175:diagnosis / Q000503:physiopathology / Q000628:therapy*; D006255:Rhinitis, Allergic, Seasonal / Q000150:complications / Q000175:diagnosis / Q000503:physiopathology / Q000628:therapy*; D012720:Severity of Illness Index; D011795:Surveys and Questionnaires; D055815:Young Adult