Chronic obstructive pulmonary disease is missed in asthmatics in specialty care in Trinidad, West Indies.

ABSTRACT

SETTING: Underdiagnosis of chronic obstructive pulmonary disease (COPD) in asthmatics attending specialty care in Trinidad, West Indies. OBJECTIVE: To determine the prevalence of COPD in diagnosed asthmatics receiving specialty respiratory care. DESIGN: In a cross-sectional study, 258 asthmatics were screened for lung function measures to examine forced expiratory volume after 1 second (FEV1), forced vital capacity (FVC) and post-bronchodilator FEV1/FVC (COPD was defined as FEV1/FVC < 70 per cent). RESULTS: Of 165 patients evaluated (response rate 64.0 per cent), 53 (32.1 per cent, 95 per centCI 25.0-39.2) had a study diagnosis of COPD and a mean FEV1/FVC of 60.12 +/- 1.2. Proportionally, more males had COPD (50.9 per cent) than asthma (24.1 per cent, P < 0.001). Patients with COPD were 10 years older than asthmatics (P < 0.001). Persons with asthma who smoked were more likely to have COPD (56.0 per cent) (OR 3.26, 95 per cent CI 1.36-7.80, P = 0.006). In both sexes, FEV1/FVC was lower among older people (P < 0.001), with a greater effect (OR 2.75, 95 per cent CI 1.00-7.56, P < 0.01) seen among men in this cross-sectional study. CONCLUSIONS: One third of diagnosed asthmatics in specialty care also have COPD. Lung function was lower among older persons. Early spirometric evaluation of elderly asthmatics who smoke can determine the presence of COPD and facilitate appropriate management.