title: Development and validation of the Chronic Obstructive Pulmonary Disease Assessment Questionnaire (COPD-AQ).
abstract: OBJECTIVE
  To develop a practical patient-completed chronic obstructive pulmonary disease assessment questionnaire (COPD-AQ) to improve COPD assessment and management in primary care, based on the concept of COPD stability.
  
  
  METHODS
  An Expert Working Group defined parameters of COPD stability and a 10-item Physician's Global Assessment was established. A 21-item COPD-AQ was developed and validated in a cross-sectional, non-randomised study of patients with COPD (n=395). Items most discriminative of stability status (stable/unstable) were selected to produce a 5-item COPD-AQ, which was then validated.
  
  
  RESULTS
  In the development sample, internal consistency reliability of the 5-item COPD-AQ was 0.74 (n=296). The COPD-AQ discriminated between stability groups based on physician assessment (F=44.26; p<0.0001) and post-bronchodilator spirometry measures (F=2.92; p<0.05). A questionnaire score >20 (range: 5.0-25.0) had a specificity of 82.9% and sensitivity of 64.7%.
  
  
  CONCLUSIONS
  The 5-item COPD-AQ proved a practical tool for assessing COPD status and was sufficiently simple for routine clinical use. However, overall validation was limited by small numbers of patients in the validation sample. Difficulties also existed over using the term 'stability' to define COPD status. COPD-AQ was not progressed further, but this work will prove valuable in the future development of a global questionnaire to improve COPD management in primary care.
authors.affiliation: University of Alabama Lung Health Center, University of Alabama, Birmingham, AL 35249, USA. wcbailey@uab.edu
authors.forename: William C
authors.initials: WC
authors.lastname: Bailey
authors.forename: Frank C
authors.initials: FC
authors.lastname: Sciurba
authors.forename: Nicola A
authors.initials: NA
authors.lastname: Hanania
authors.forename: James F
authors.initials: JF
authors.lastname: Donohue
authors.forename: Gary T
authors.initials: GT
authors.lastname: Ferguson
authors.forename: Joseph D
authors.initials: JD
authors.lastname: Zibrak
authors.forename: Amir
authors.initials: A
authors.lastname: Sharafkhaneh
authors.forename: Philip
authors.initials: P
authors.lastname: Marcus
authors.forename: Kathleen
authors.initials: K
authors.lastname: Rosa
authors.forename: Elisabeth C
authors.initials: EC
authors.lastname: Piault
authors.forename: Fernando J
authors.initials: FJ
authors.lastname: Martinez
mesh_terms: D000368:Aged; D018450:Disease Progression; D006801:Humans; D008875:Middle Aged; D011237:Predictive Value of Tests; D029424:Pulmonary Disease, Chronic Obstructive / Q000175:diagnosis*; D012372:ROC Curve; D012720:Severity of Illness Index; D011795:Surveys and Questionnaires