['Underdiagnosis of chronic obstructive pulmonary disease (COPD) in asthmatics attending specialty care in Trinidad, West Indies.', 'To determine the prevalence of COPD in diagnosed asthmatics receiving specialty respiratory care.', '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%).', 'Of 165 patients evaluated (response rate 64.0%), 53 (32.1%, 95%CI 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%) than asthma (24.1%, 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%) (OR 3.26, 95%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%CI 1.00-7.56, P < 0.01) seen among men in this cross-sectional study.'] Is chronic obstructive pulmonary disease missed in asthmatics in specialty care in Trinidad , West Indies?