Spirometry is known to be a gold standard for the diagnosis of chronic obstructive pulmonary disease (COPD). COPD Assessment Test (CAT) is an eight-item questionnaire currently in use to evaluate patients with COPD. In the present study, we aimed to evaluate if CAT is an adequate tool for screening COPD.

In total, 600 persons aging ⩾40 years old were randomly selected from three different family practice units located in the city center. CAT was asked to the participants and a spirometry was used to assess pulmonary obstruction. Pulmonary obstruction was defined as forced expiratory volume in first second/forced vital capacity (FEV1/FVC)<70% and then COPD diagnosis was confirmed with the reversibility test. The relationship between CAT results and pulmonary function test values was evaluated.

In this sampling, the prevalence of COPD was 4.2%. Reliability of the CAT in the study group was acceptable (Cronbach’s α: 0.84). The CAT scores was significantly higher in patients with COPD (P<0.001). There was a significant negative correlation between CAT score and FEV1, FVC and FEV1/FVC ratio (r=−0.31, P<0.001; r=−0.26, P<0.001; r=0.18, P=0.001). Among smokers, phlegm was the predominating symptom (P=0.01). Sensitivity of CAT was 66.67% and its specificity was 75.15% to determine COPD.

CAT is a reliable questionnaire and there is an apparent relationship between the total CAT scores and COPD. However, CAT’s ability to screen COPD is limited since it may miss the symptom-free cases.