title: The structure of symptom report in asthma: a reevaluation.
abstract: OBJECTIVE
  We studied the structure of symptom report in a sample of British asthma patients using the Asthma Symptom Checklist (ASC).
  
  
  METHODS
  The ASC was administered to 193 patients, together with a questionnaire on demographics and asthma-related information and the Perceived Control of Asthma Questionnaire.
  
  
  RESULTS
  Principal Component Analysis yielded evidence for a six-dimensional structure of the ASC, with positively correlated subscales for panic-fear, irritation, obstruction-dyspnea, obstruction-congestion, fatigue, and hyperventilation symptoms. Individual subscales showed good to excellent item characteristics and internal consistencies in individual subscales. Panic-fear and obstruction-congestion were related to self-reported duration of oral corticosteroid intake. Other ASC subscales were positively related to aspects of health care utilization, limitations in daily activity, and lower perceived control of asthma mainly in women. The dyspnea subscale of the ASC showed only little relationship with either of these variables.
  
  
  CONCLUSIONS
  The ASC can reliably assess the multidimensional structure of asthma symptom report. Its subscales are associated with important aspects of asthma management behavior.
authors.affiliation: Department of Psychology, St. George's Hospital Medical School, University of London, London, UK. tritz@stanford.edu
authors.forename: T
authors.initials: T
authors.lastname: Ritz
authors.forename: C
authors.initials: C
authors.lastname: Bobb
authors.forename: M
authors.initials: M
authors.lastname: Edwards
authors.forename: A
authors.initials: A
authors.lastname: Steptoe
mesh_terms: D000284:Administration, Oral; D000293:Adolescent; D000328:Adult; D000368:Aged; D000402:Airway Obstruction / Q000453:epidemiology / Q000523:psychology; D000893:Anti-Inflammatory Agents / Q000627:therapeutic use; D001249:Asthma / Q000175:diagnosis* / Q000188:drug therapy; D004417:Dyspnea / Q000175:diagnosis / Q000453:epidemiology; D005260:Female; D006801:Humans; D006985:Hyperventilation / Q000175:diagnosis / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D016584:Panic Disorder / Q000453:epidemiology / Q000523:psychology; D015203:Reproducibility of Results; D012646:Self Administration; D013256:Steroids; D011795:Surveys and Questionnaires
chemical_list: D000893:Anti-Inflammatory Agents; D013256:Steroids