The COPD assessment test (CAT) assists prediction of COPD exacerbations in high-risk patients.
We evaluated the predictive value of the COPD assessment test (CAT™) for exacerbation in the following six months or time to first exacerbation among COPD patients with previous exacerbations. COPD outpatients with a history of exacerbation from 19 hospitals completed the CAT questionnaire and spirometry over six months. Exacerbation events were prospectively collected using a structured questionnaire. The baseline CAT score categorised into four groups (0-9, 10-19, 20-29, and 30-40) showed strong prediction for time to first exacerbation and modest prediction for any exacerbation or moderate-severe exacerbation (AUC 0.83, 0.64, and 0.63 respectively). In multivariate analyses, the categorised CAT score independently predicted all three outcomes (p = 0.001 or p < 0.001). Compared with the lowest CAT score category, the higher categories were associated with significantly shorter time to first exacerbation and higher exacerbation risks. The corresponding adjusted median time was >24, 14, 9, and 5 weeks and the adjusted RR was 1.00, 1.30, 1.37, and 1.50 in the category of 0-9, 10-19, 20-29, and 30-40 respectively. Exacerbation history (≥2 vs. 1 event in the past year) was related to time to first exacerbation (adjusted HR 1.35; p = 0.023) and any exacerbation during the study period (adjusted RR 1.15; p = 0.016). The results of this study support the use of the CAT as a simple tool to assist in the identification of patients at increased risk of exacerbations. This could facilitate timely and cost-effective implementation of preventive interventions, and improve health resource allocation.


BACKGROUND
Clinicaltrials.gov: NCT01254032.
Division of Pulmonary and Critical Care Medicine, Asan Medical Center, University of Ulsan College of Medicine, 388-1 Pungnap-2-dong, Songpa-gu, Seoul 138-736, Republic of Korea.
Sang-Do
SD
Lee
Department of Internal Medicine, Kaohsiung Medical University Hospital, School of Medicine, Kaohsiung Medical University, No. 100, Tzyou 1st Road, Kaohsiung 807, Taiwan.
Ming-Shyan
MS
Huang
The Institute of Respiratory Diseases, The First Affiliated Hospital of China Medical University, No. 117, Nanjing Street (N), Shenyang 110001, Liaoning, China.
Jian
J
Kang
Division of Chest Medicine, Department of Internal Medicine, Changhua Christian Hospital, No. 135, Nan-Hsiao Street, Changhua City, Changhua County 500, Taiwan.
Ching-Hsiung
CH
Lin
Division of Respiratory and Critical Care Medicine, Kyung Hee University Hospital, Kyung Hee University, 1 Hoegi-dong, Dongdaemun-gu, Seoul 130-702, Republic of Korea.
Myung Jae
MJ
Park
Division of Pulmonary and Critical Care Medicine, Asan Medical Center, University of Ulsan College of Medicine, 388-1 Pungnap-2-dong, Songpa-gu, Seoul 138-736, Republic of Korea.
Yeon-Mok
YM
Oh
Asia Pacific Medical, GlaxoSmithKline, 150 Beach Road, #22-00 Gateway West, Singapore 189720, Singapore.
Namhee
N
Kwon
Division of Clinical Science, St George's University of London, Cranmer Terrace, London SW17 0RE, United Kingdom.
Paul W
PW
Jones
Australian Respiratory and Sleep Medicine Institute, Flinders Medical Centre, Bedford Park, Adelaide, SA 5042, Australia. Electronic address: dimitar.sajkov@health.sa.gov.au.
Dimitar
D
Sajkov
D000368:Aged; D018450:Disease Progression; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D011379:Prognosis; D011446:Prospective Studies; D029424:Pulmonary Disease, Chronic Obstructive / Q000175:diagnosis* / Q000188:drug therapy; D012307:Risk Factors; D012720:Severity of Illness Index; D013147:Spirometry / Q000379:methods
COPD assessment test; Chronic obstructive pulmonary disease; Exacerbation; Prediction