The role of CAT in evaluating the response to treatment of patients with AECOPD

Abstract

Background

The chronic obstructive pulmonary disease (COPD) Assessment Test (CAT) questionnaire is a short patient-completed questionnaire, which is used to assess the health status of patients with stable COPD. However, whether it is a good tool to evaluate the response to treatment in acute exacerbation of COPD (AECOPD) has been less studied.

Methods

The patients were assessed at two visits, at admission and on the seventh day. Anthropometric variables were collected at admission. CAT and lung function were measured twice at the above time points. At the second visit, the health status of the patients were divided into five groups based on a 5-point Likert scale, ranging from 1 to 5, which represents “much better,” “slightly better,” “no change,” “slightly worse,” and “much worse.” Responders were those who reported “much better” or “slightly better,” and nonresponders were those who claimed “no change,” “worse,” or “much worse.”

Results

In total, 225 patients were recruited. The average CAT score at admission was 24.82±7.41, which declined to 17.41±7.35 on the seventh day. There were 81.33% responders, whose improvement in CAT score (9.37±5.24) was much higher than that of the nonresponders (−1.36±4.35). A moderate correlation was observed between the changes in CAT score and improvement in FEV₁, FEV₁%, and the length of hospital stay. There was a strong correlation between the changes in CAT score and health status. A 3.5-unit improvement in the CAT score, with highest area under the curve, was the cutoff to differentiate responders from nonresponders.

Conclusion

The evolution of CAT scores during exacerbation can provide useful information to assess the health status of patients with AECOPD. A 3.5-unit improvement in CAT score is the best cutoff to differentiate between patients who have a response or no response to treatment, which offers a convenient and easy way for clinicians to monitor the health status of patients with an AECOPD.

Keywords:

• COPD
• acute exacerbation
• CAT
• curative effect

Supplementary materials

Figure S1 The number of the patients who received standard treatment.

Notes: This was a one-year follow-up study. In total, 189 patients were recruited into our study. All of them accepted three visits after being recruited (at 3 months, at 6 months, and at 12 months). If the patients reported they took their drugs everyday based on the prescription at every visit, they would be classified as those who received regular treatment. The rest were those who didn’t receive regular treatment. We found that only one-third of the patients received regular treatment.

Table S1 The detailed information of the comorbidities of patients who reported no change

Acknowledgments

This study was funded by grants from the National Natural Science Foundation of China (NSFC, Grants 81770046 to Prof Ping Chen) and Fundamental Research Funds for the Central Universities of Central South University (2017zzts228 to Dr Aiyuan Zhou).

Author contributions

PC and AZ contributed to the study design; AZ contributed to the drafting of the manuscript; PC contributed to critically revising the manuscript for important intellectual content. AZ, ZZ, YP, YZ, and JD contributed to data collection. All authors contributed toward data analysis, drafting, and revising the paper, and agree to be accountable for all aspects of the work.

Disclosure

The authors report no conflicts of interest in this work.