The course of clinical COPD in Thailand.

Spirometry and outcome of 96 cases who were clinically diagnosed as having COPD were studied. Ninety-two cases had significant airway obstruction. Of these 92 cases, initial bronchodilator responses were evaluated in 73 cases. Twenty-six cases were responders (CRAO), while 47 cases were nonresponders (COPD). The average median survival of the whole group was 4 years and 5-year survival was 30 per cent. The annual change in FEV1 in both COPD and CRAO group were fluctuating, with a tendency to decrease in the former and increase in the latter. Spirometric parameters were found to be different between the survivors and nonsurvivors, these included initial PFEV1, PFVC, PFEF 25-75 per cent and postbronchodilator FEV1 and FEF 25-75 per cent. Inspite of the differences, an initial response to bronchodilator could not predict a better outcome for CRAO as compared to COPD. It was concluded that most clinical COPD who had progressive symptoms had significant airway obstruction and shorter survival. Due to fluctuating FEV1 during the course, the initial spirometry and degree of bronchodilator response were not accurate enough to predict subsequent outcome. Long-term follow-up on spirometry and response to bronchodilator should be individually evaluated.