Clinical Characteristics of COPD Patients According to COPD Assessment Test (CAT) Score Level: Cross-Sectional Study

Abstract

Purpose The chronic obstructive pulmonary disease (COPD) assessment test (CAT) is widely used to assess the impact of COPD symptoms on health status. Whilst the CAT consists of eight different items, details on the distribution of each item are limited. This study aimed to investigate the distribution and clinical implication of each CAT item, stratified by CAT severity group, in stable COPD patients. Patients and Methods This was a cross-sectional study at a single referral hospital in South Korea. Spirometry confirmed COPD patients with CAT measured at the first clinical visit were retrospectively identified. Patients were categorized into three groups: low (0 ≤ CAT < 10), medium (10 ≤ CAT < 20), and high (20 ≤ CAT ≤ 40) impact group. For the purpose of this analysis, the first four items (cough, sputum, chest tightness, and dyspnea) and the remaining four items (activities, confidence, sleep and energy) were also grouped as “pulmonary” and “extra-pulmonary”, respectively. Results A total of 815 patients were included, and mean (SD) forced expiratory volume in 1 s (FEV 1 ) was 62.8 (17.4) % pred. Among them, 300 patients (36.8%) were in the high impact group and had a greater exacerbation history and lower lung function. The proportion of “extra-pulmonary” items score was greater in patients with higher total CAT scores, with the activity and confidence items showing higher scores. Conclusion In our study, in addition to dyspnea, activity limitation is a particular problem in individual patients with higher CAT total scores, for which physicians need to pay more attention. Our study suggests that whilst CAT total score captures the overall impact of COPD, each item of the CAT contains potentially useful information in understanding the patient’s symptom burden.

Change in individual chronic obstructive pulmonary disease assessment test item scores after short-term bronchodilator therapy and its impact on exacerbation in treatment-naïve patients with chronic obstructive pulmonary disease

“…Although the CAT was developed to be unidimensional and without subdomains, 8 the items can be pragmatically grouped into two groups based on their content: cough, phlegm, chest tightness, and breathlessness as ‘pulmonary items’; and activities, confidence, sleep, and energy as ‘extra-pulmonary items’. 18 , 20 In our study, scores for phlegm, chest tightness, and breathlessness items of the CAT remarkably improved after short-term bronchodilator therapy in all patients. Scores for items five through eight (activities, confidence, sleep, and energy), classified as ‘extra-pulmonary’, did not show any change.…”

“… 15 – 17 Recent studies have shown that each CAT item contains additional information and contributes differently to the total score. 18 – 20 However, to the best of our knowledge, there are a few data primarily focusing on changes in each CAT item after bronchodilator therapy initiation and its association with other clinical factors. Thus, we investigated changes in individual CAT scores after short-term bronchodilator therapy among treatment-naïve patients with COPD and compared lung function, mMRC dyspnea, and exacerbations between patients whose CAT scores improved and those whose CAT scores did not.…”

Value of Cardiopulmonary Exercise Testing in the Prognosis Assessment of Chronic Obstructive Pulmonary Disease Patients: A Retrospective, Multicentre Cohort Study

“…In our prognosis models, dyspnoea and age were also significantly associated with survival. It has long been known that the degree of dyspnoea has significantly more prognostic relevance than grading according to lung function values in patients with COPD [33][34][35][36]. Dyspnoea is a substantial correlate of hyperinflation in patients with COPD, which often results in dynamic hyperinflation and disturbance of ventilatory efficiency [2].…”

Components of the Chronic Obstructive Pulmonary Disease Assessment Test Associated with the Exacerbation of Severe Chronic Obstructive Pulmonary Disease Patients

“…Although the results of our study are consistent with previous publications demonstrating that patients with elevated CAT scores frequently experienced acute exacerbations, these studies primarily considered total CAT scores [18,29,30], and a scarcity of studies have focused on each component of the CAT. Recent studies showed that patients with higher total CAT scores had a greater proportion of highly scored items related to non-respiratory issues [31,32]. Gil and colleagues [32] reported that CAT items related to activity and confidence showed particularly rapid deterioration in patients with high CAT impact.…”