Determinants of high chronic obstructive pulmonary disease assessment test scores according to airflow limitation severity: a three-year prospective study

The determinants of chronic obstructive pulmonary disease (COPD) assessment test (CAT) scores according to airflow limitation severity are not fully understood. We aimed to elucidate this by analyzing data from 378 patients with COPD, categorized into two groups based on airflow limitation severity (FEV1 > 50% [GOLD-mild] and ≤ 50% [GOLD-severe]). Within each severity group, patients were further sub-stratified by CAT score (≥ 10 vs. <10). Patients with CAT scores ≥ 10 in the GOLD-mild group were older, with more severe airflow limitation and higher prevalence of gastroesophageal reflux disease (GERD), anxiety, depression, and diabetes, whereas those in the GOLD-severe group showed higher GERD and asthma prevalences. GERD and asthma contributed predominantly to respiratory-specific items. Airflow limitation and GERD were strong determinants in both severity groups. Key determinants were anxiety and depression in the GOLD-mild group and asthma in the GOLD-severe group. These associations remained consistent over 3 years. These findings offer valuable insights for managing patients with pronounced subjective symptoms in COPD.