Prevalence of Airflow Obstruction in Nonsmoking Older Individuals Using Different Spirometric Criteria: The AGES Reykjavik Study

Abstract

Background: The prevalence and characteristics of airway obstruction in older individuals varies widely with the definition used. We used a random sample of never smoking older population in Iceland to compare the prevalence and clinical profile of subjects diagnosed with Chronic Obstructive Pulmonary Disease (COPD) based on different spirometric criteria. Material and methods: The study uses data from the Age, Gene/Environment Susceptibility–Reykjavik Study, comprising survivors from the Reykjavik Study. Procedures included standardized questionnaires and pre-bronchodilator spirometry for measurement of forced expiratory volume in one second (FEV1) and forced vital capacity (FVC). Results: Total of 495 individuals (150 men and 345 women) met study criteria. Mean age 77 years (range 66-92 years) using fixed ratio (FEV1/FVC < 70%) up to 29% of the population were diagnosed with COPD Stage I. The prevalence of COPD increased with age. Only 7 among 495 (1.4%) were diagnosed with COPD using FEV1/FVC LLN and FEV1 LLN. Conclusion: Application of the GOLD criteria for diagnosis of COPD in older lifelong never smoking subjects identifies a substantial number of non-symptomatic subjects as having COPD. If airway obstruction is defined by FEV1/FVC and FEV1 being below the LLN using appropriate reference equations, only very few non-smoking older individuals fulfill the criteria for COPD.

Keywords :

• Older individuals
• Chronic Obstructive Pulmonary Disease
• spirometry
• lower limit of normal
• co-morbidities