Abstract
Background: No short patient-reported outcome (PRO) instruments assess overall health status across different obstructive lung diseases. Thus, the wording of the introduction to the Chronic Obstructive Pulmonary Disease (COPD) Assessment Test (CAT) was modified to permit use in asthma and/or COPD. This tool is called the Chronic Airways Assessment Test (CAAT).
Methods: The psychometric properties of the CAAT were evaluated using baseline data from the NOVELTY study (NCT02760329) in patients with physician-assigned asthma, asthma+COPD or COPD. Analyses included exploratory/confirmatory factor analyses, differential item functioning and
analysis of construct validity. Responses to the CAAT and CAT were compared in patients with asthma+COPD and those with COPD.
Results: CAAT items were internally consistent (Cronbach’s alpha: >0.7) within each diagnostic group (n=510). Models for structural and measurement invariance were strong. Tests of differential item functioning showed small differences between asthma and COPD in individual items, but these were not consistent in direction and had minimal overall impact on the total score. The CAAT and CAT were highly consistent when assessed in all NOVELTY patients who completed both (N=277, Pearson’s correlation coefficient: 0.90). Like the CAT itself, CAAT scores correlated moderately (0.4– 0.7) to strongly (>0.7) with other PRO measures and weakly (Conclusions: CAAT scores appear to reflect the same health impairment across asthma and COPD, making the CAAT an appropriate PRO instrument for patients with asthma and/or COPD. Its brevity makes it suitable for use in clinical studies and routine clinical practice.
Methods: The psychometric properties of the CAAT were evaluated using baseline data from the NOVELTY study (NCT02760329) in patients with physician-assigned asthma, asthma+COPD or COPD. Analyses included exploratory/confirmatory factor analyses, differential item functioning and
analysis of construct validity. Responses to the CAAT and CAT were compared in patients with asthma+COPD and those with COPD.
Results: CAAT items were internally consistent (Cronbach’s alpha: >0.7) within each diagnostic group (n=510). Models for structural and measurement invariance were strong. Tests of differential item functioning showed small differences between asthma and COPD in individual items, but these were not consistent in direction and had minimal overall impact on the total score. The CAAT and CAT were highly consistent when assessed in all NOVELTY patients who completed both (N=277, Pearson’s correlation coefficient: 0.90). Like the CAT itself, CAAT scores correlated moderately (0.4– 0.7) to strongly (>0.7) with other PRO measures and weakly (Conclusions: CAAT scores appear to reflect the same health impairment across asthma and COPD, making the CAAT an appropriate PRO instrument for patients with asthma and/or COPD. Its brevity makes it suitable for use in clinical studies and routine clinical practice.
Original language | English |
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Article number | 106 |
Number of pages | 13 |
Journal | Respiratory Research |
Volume | 24 |
Early online date | 8 Apr 2023 |
DOIs | |
Publication status | Published - 8 Apr 2023 |
Bibliographical note
AcknowledgementsThe authors would like to thank the patients who participated in this study and wish to acknowledge the work of the NOVELTY Scientific Community and the NOVELTY study investigators, who are listed in full below, and Sharon MacLachlan (Evidera, London, UK), who participated in the analysis of sections of the data. Medical writing support, under the direction of the authors, was provided by Niall Tyrer, MBiolSci, CMC Connect, a division of IPG Health Medical Communications, funded by AstraZeneca, Cambridge, UK, in accordance with Good Publication Practice (GPP 2022) guidelines (Ann Intern Med 2022; 175(9):1298–1304).
Funding
The NOVELTY study was funded by AstraZeneca.
Keywords
- Asthma
- COPD
- patient-reported
- psychometrics
- chronic airways assessment test
- COPD assessment test