Clinical, physiological and psychosocial determinants of the COPD Assessment Test (CAT).

Background:

The CAT is a simple eight-item patientcompleted questionnaire and could be used in clinical practice.



Objectives:

Study clinical, physiological and psychosocial determinants of CAT in a broad sample of patients with moderate to very severe COPD and the impact of co-morbidities on health status assessed with CAT; assess the effects of pulmonary rehabilitation on CAT scores in COPD patients; formulate reference values for CAT using healthy controls; validate CAT in a broad sample of COPD patients.



Study design:

Cross sectional observational study with a longitudinal part for tertiary care patients.



Study population:

Broad range of COPD patients (100 COPD patients from primary care setting, 100 COPD patients from secondary care and 600 COPD patients of the tertiary care) between 40 and 85 years old and 150 healthy controls.



Primary study parameters/outcome of the study:

CAT scores of COPD patients and healthy controls; change in CAT score before and after rehabilitation; correlates of CAT scores (i.e., health status questionnaires, co-morbidity, other potential confounders).

1. (Previously undiagnosed) cardiovascular disease (heart failure/vascular abnormalities/coronary artery disease), metabolic syndrome and other co-morbidities are additional independent predictors of impaired health status, assessed with CAT, in patients with COPD, irrespective of the severity of airflow limitation;

2. CAT is responsive to a comprehensive pulmonary rehabilitation programme in patients with COPD;

3. COPD patients have worse scores on the CAT than healthy elderly subjects;

4. CAT is a valid instrument to assess health status in patients with mild to very severe COPD;

5. CAT scores correlate well with other questionnaires (i.e., SGRQ-C, CCQ).

All participants have one baseline visit to collect the data of the study. Only tertiary care patients have two visits, one before and one after pulmonary rehabilitation.

There is no intervention. Tertiary care patients will receive a regular pulmonary rehabilitation program which is part of their routine treatment.