Reliable test for COPD exacerbations
Friday, 27 January 2012
The COPD Assessment Test™ (CAT) is a reliable tool for assessing the severity of exacerbations in people with chronic obstructive pulmonary disease, say UK researchers. Their study has been published early online in the American Journal of Respiratory and Critical Care Medicine.
The authors, lead by Dr Alex Mackay from University College London’s Academic Unit of Respiratory Medicine, have welcomed the long-awaited availability of a free, easy to administer and objective way in which to assess symptom severity.
They asked 161 COPD patients to complete the CAT health status questionnaire under clinic supervision. It comprises just eight items, that assess cough, phlegm, chest tightness, breathlessness, activity limitations, sleep, and energy levels. The CAT was also answered by 75 patients during 152 treated exacerbations of COPD.
Patients who had at least two COPD exacerbations a year had significantly higher CAT scores at baseline than those with less frequent exacerbations.
CAT scores rose significantly during the 152 exacerbations. There was a significant but weak association between the change in CAT score from baseline to exacerbation, and change in CRP – bit not with change in fibrinogen. There were also significant associations between the rise in CAT score with an exacerbation, and the fall in forced expiratory volume in one second (FEV1); and between median recovery time (determined with symptom diaries) and the time take for CAT scores to return to baseline level.
Dr Mackay said: “In our patients with COPD, CAT scores reflected exacerbation severity, as measured by both exacerbation length and reduction in lung function. CAT scores at exacerbation were also weakly related to systemic inflammatory markers and were elevated in stable patients with a history of frequent exacerbations.
“Our results indicate that the CAT can be used as a score of the multi-dimensional nature of COPD exacerbation severity.”
He concluded: “The CAT is validated, free, and easy to administer, and can be easily incorporated into the usual care of patients with COPD at no additional cost.”