Prevalence of chronic obstructive pulmonary disease according to BTS, ERS, GOLD and ATS criteria in relation to doctor's diagnosis, symptoms, age, gender, and smoking habits

Background: Guidelines and standards for diagnosis and management of chronic obstructive pulmonary disease (COPD) have been presented by different national and international societies, but the spirometric criteria for COPD differ between guidelines.

Objectives: To estimate prevalence of COPD using the guidelines of the British Thoracic Society (BTS), the European Respiratory Society (ERS), the Global Initiative for Chronic Obstructive Lung Disease (GOLD), and the American Thoracic Society (ATS). Further, to evaluate reported airway symptoms, contacts with health care providers, and physician diagnosis of COPD in relation to the respective criteria, and gender differences.

Method: In 1992 a postal questionnaire was sent to a random sample of adults aged 20-69 years, 4,851 (85%) out of 5,681 subjects responded. In 1994-1995 a random sample of the responders, 970 subjects, were invited to a structured interview and a lung function test; 666 (69%) participated.

Results: The prevalence of COPD was 7.6, 14.0, 14.1, 12.2 and 34.1% according to BTS, ERS, GOLD, clinical ATS (with symptoms or physician diagnosis), and spirometric ATS criteria, respectively. Prevalent COPD was related to age, smoking habits and family history of obstructive airway disease but not to gender. Physician diagnosis of chronic bronchitis or emphysema was only reported by 16.3, 12.2, 11.0, 23.4 and 8.2% of subjects fulfilling the respective criteria, though a majority reported airway symptoms.

Conclusion: The main determinants for prevalent COPD were age, smoking habits and spirometric criteria of COPD. Though a majority reported airway symptoms and contact with health care providers due to respiratory complaints, only a minority was diagnosed as having COPD, indicating a large underdiagnosis.