Korean J Intern Med.  2015 Sep;30(5):629-637. 10.3904/kjim.2015.30.5.629.

Chronic obstructive pulmonary disease (COPD) assessment test scores corresponding to modified Medical Research Council grades among COPD patients

• Lee CH
• Lee J
• Park YS
• Lee SM
• Yim JJ
• Kim YW
• Han SK
• Yoo CG

• KMID: 2381561
• DOI: http://doi.org/10.3904/kjim.2015.30.5.629

Abstract

BACKGROUND/AIMS
In assigning patients with chronic obstructive pulmonary disease (COPD) to subgroups according to the updated guidelines of the Global Initiative for Chronic Obstructive Lung Disease, discrepancies have been noted between the COPD assessment test (CAT) criteria and modified Medical Research Council (mMRC) criteria. We investigated the determinants of symptom and risk groups and sought to identify a better CAT criterion.
METHODS
This retrospective study included COPD patients seen between June 20, 2012, and December 5, 2012. The CAT score that can accurately predict an mMRC grade > or = 2 versus < 2 was evaluated by comparing the area under the receiver operating curve (AUROC) and by classification and regression tree (CART) analysis.
RESULTS
Among 428 COPD patients, the percentages of patients classif ied into subgroups A, B, C, and D were 24.5%, 47.2%, 4.2%, and 24.1% based on CAT criteria and 49.3%, 22.4%, 8.9%, and 19.4% based on mMRC criteria, respectively. More than 90% of the patients who met the mMRC criteria for the 'more symptoms group' also met the CAT criteria. AUROC and CART analyses suggested that a CAT score > or = 15 predicted an mMRC grade > or = 2 more accurately than the current CAT score criterion. During follow-up, patients with CAT scores of 10 to 14 did not have a different risk of exacerbation versus those with CAT scores < 10, but they did have a lower exacerbation risk compared to those with CAT scores of 15 to 19.
CONCLUSIONS
A CAT score > or = 15 is a better indicator for the 'more symptoms group' in the management of COPD patients.

Keyword

Pulmonary disease, chronic obstructive; Symptoms; Classification; COPD assessment test; Modified Medical Round Council

MeSH Terms

Aged
Algorithms
Area Under Curve
*Decision Support Techniques
Decision Trees
Female
Humans
Lung/*physiopathology
Male
Middle Aged
Predictive Value of Tests
Pulmonary Disease, Chronic Obstructive/classification/*diagnosis/physiopathology
ROC Curve
Regression Analysis
Reproducibility of Results
Republic of Korea
Retrospective Studies
Risk Factors
Severity of Illness Index