Role of Screening Lung Function Tests in a Routine Health Checkup

Background and objectives The lung function test is a gold standard, guideline-recommended test to detect obstructive airway diseases like asthma and COPD. It is of considerable value in detecting the presence and severity of airflow obstruction in patients with respiratory symptoms. However, the role of spirometry in a routine health checkup is controversial. Spirometry, when used in routine health checkup settings as a case-finding tool for all adults with persistent respiratory symptoms or having a history of exposure to risk factors, is likely to label a relatively large proportion of individuals as diseased with airflow obstruction. Conversely, spirometry is normal in a relatively large percentage of adults who report respiratory symptoms including dyspnea, the respiratory symptom having the greatest impact on quality of life. The objective of this study is to determine the utility of spirometry as a screening test to detect airflow obstruction in otherwise healthy subjects undergoing a routine health checkup. Methods This observational study was conducted with 538 health checkup individuals aged 18 and over. A brief history was taken prior to the test. Lung function tests were performed and interpreted as per the Global Initiative for Chronic Obstructive Lung Disease criteria. The anthropometric and spirometric data obtained were compared to other population-based spirometric studies to compare the prevalence of airflow limitation, the risk factors, and smoking history. Results Of the total 538 subjects incorporated in the study, 305 (57%) were males and 233 (43%) were females aged between 18 to 80 years with a mean age of 45 years. The male-to-female ratio was 1.3:1 with a mean BMI of 25.9. The overall yield from lung function tests in detecting airflow obstruction was 63 subjects (11.7%), of which 36 (11.8%) were males and 27 (11.5%) were females. Seventy-three subjects (13.5%) were classified as having a small airway obstruction, of which 34 were males (46.6%), and 39 were females (53.4%). The distribution of airflow obstruction by age was with eight subjects (5.4%) in the 18-35 group, 21 subjects (7.8%) in the 36-55 group, and 34 (25%) in the elderly (>55) age group. Although overall smoking history showed no significant association with developing airflow obstruction, significant association with smoking was found in the elderly (>55) age group. Interpretation and conclusions The results of the study suggest that lung function tests should be included in routine health checkups in the subset of individuals greater than 35 years of age with or without a history of smoking, in all age groups with a family history of asthma, in individuals with respiratory symptoms and in individuals greater than 55 years of age with a moderate history of smoking.