Usefulness of the COPD assessment test (CAT) in primary care.

Optimum management of COPD can improve prognosis and reduce the impact of the disease on quality of life and health status. For this purpose, optimal assessments of multiple dimensions of the disease are necessary. Previous guideline recommendations were often based on limited evidence of therapeutic effectiveness and limited study of the feasibility of incorporating recommendations into primary care. Assessment of COPD severity was based solely on the degree of bronchial obstruction, despite a weak correlation between lung function parameters and perceived symptoms and limitations. However, current guidelines recommend assessment of patientfocused outcomes; these can be measured using various validated health status measures, from the simple one-question Medical Research Council (MRC) dyspnoea grade to the more complex St George’s Respiratory Questionnaire (SGRQ). The difficult question is how we should incorporate patientrelated outcome measures into routine primary care practice. One solution has been to use composite measures of disease severity including lung function and health status. The BODE index (Body mass index, Obstruction, Dyspnea, Exercise) uses the MRC as a measure of health status and has proved to be robust as a measure of disease severity and prognosis, but is not widely used in routine care. The latest GOLD guidelines suggest dividing patients into four categories based on current symptoms (assessed using the MRC or the COPD assessment test (CAT)), percent predicted FEV1, and the number of exacerbations. However, this system has met with significant objections since it was neither derived nor validated statistically, is complex to use, and may not be suitable for primary care. Valid and reliable tools for health status measurement in COPD patients are beneficial for comparative studies between populations as well as for measuring shortand long-term changes, perhaps especially for health authorities, researchers and pharmaceutical companies. Pivotal questions remain, however, such as whether these tools improve the communication between health professional and patient, contribute to improved patient outcomes, or if they are feasible to use in routine general practice. Newer scales could facilitate use in routine care. One of the aims during the development of the CAT was to improve communication between COPD patients and the clinician, thus enabling a common understanding of the severity and impact of the disease. This is not easy to determine, but in this issue of the PCRJ, Gruffydd-Jones et al. report a very interesting randomised controlled study on the utility of the CAT in primary care consultations. As many as 165 primary care physicians from six European countries conducted six consultations with standardised COPD patients (played by trained actors) covering a variety of COPD severities and co-morbidities. Physicians were randomised to see the patients in videoed consultations with or without the completed CAT. The physicians were scored according to their ability to identify and address A) relevant patient issues, and B) ten standard COPD issues, as well as being scored on their understanding of the case and their overall performance in 10-minute consultations. The physicians with access to the completed CAT more often achieved “high quality reviews” of the items included in COPD sub-score B, but no difference was found between the two groups as regards questions on tobacco smoking and exacerbations, non-COPD symptoms (sub-score A), co-morbidities or other consultation quality measures. Therefore, the CAT aided primary care physician assessment of COPD-related issues but not the detection of non-COPD symptoms or co-morbidities. There are, of course, limitations in standardised studies such as this, but the authors deserve credit for performing an ingeniously-designed and important study. The Clinical COPD questionnaire (CCQ) was developed in 2003 and contains 10 items with three domains (symptoms, functional and Usefulness of the COPD assessment test (CAT) in primary care