Prevalence of chronic obstructive pulmonary disease in Japanese people on medical check-up.

In Japan, spirometry has not been included as an item in medical check-ups for all persons. The purpose of this study was to show evidence to recommend spirometry routinely on medical check-up for the early detection of chronic obstructive pulmonary disease (COPD). There were 12,760 enrolled persons who underwent medical check-up. COPD was defined as a ratio of forced expiratory volume in one second to slow vital capacity of 70% or less. We investigated the prevalence and its characteristics of COPD in people on medical check-up. The prevalence of COPD was 3.6% in all subjects, 4.5% in males, and 1.8% in females. In the comparison between males and females, the prevalence of COPD in males of most age groups was higher than that of females, and this difference was greater with aging. Males in their 50s and over 60 years old and females over 60 years old showed remarkably high prevalences. Occupations associated with a high smoking rate such as transportation-related occupations showed a higher prevalence of COPD. These results suggest that spirometry for all persons in medical check-ups can identify many COPD patients not aware of this disease. Spirometry should be carried out routinely on medical check-up.