Validity of the Chronic Airways Assessment Test (CAAT) in asthma, asthma+COPD and COPD in NOVELTY.

Abstract

Background: To assess health status in respiratory diseases, the Chronic Airways Assessment Test (CAAT) was adapted from the COPD Assessment Test (CAT) by replacing COPD-specific wording. It has demonstrated good psychometric properties in asthma and/or COPD. This cross-sectional analysis evaluated how CAAT scores are associated with clinical characteristics in patients with asthma and/or COPD.

Methods: Using baseline NOVELTY data (NCT02760329) for patients with physician-assigned asthma and/or COPD, linear regression models were implemented to assess the association between CAAT score (range 0-40; higher scores indicating worse health status) and physician-assessed severity, lung function, modified Medical Research Council dyspnoea grade, Respiratory Symptoms Questionnaire score and, for asthma and asthma+COPD, symptom control assessed by Asthma Control Test score.

Results: Among 7828 patients (asthma: 4138; asthma+COPD: 991; COPD: 2699), CAAT score was lower in patients with asthma (mean±sd 14.0±8.5) versus patients with asthma+COPD (17.2±8.6) or COPD (17.0±8.3), indicating better health status in asthma. Associations between CAAT score and clinical characteristics were similar across diagnostic groups (interaction p-values >0.01), with higher CAAT scores associated with more respiratory symptoms, greater exercise limitation due to breathlessness, lower lung function, worse physician-assessed severity and (in asthma+COPD) with worse asthma symptom control. CAAT scores among those with asthma were lower versus other diagnostic groups by physician-assessed severities. Findings were similar when adjusting for age and for age, sex and smoking status.

Conclusion: The CAAT demonstrated consistent cross-sectional validity across asthma and/or COPD, making it applicable for assessing health status in these conditions in clinical practice and research.