Chronic obstructive pulmonary disease and the mortality risk in male older adults: Role of socioeconomic factors

Objective: : Chronic obstructive pulmonary disease (COPD) is a common disease among older adults, leading to mortality. Although COPD is also associated with socioeconomic factors, little is known about the impact of COPD on mortality accounting for them. We examined the association between COPD and mortality among older male adults, adjusting for socioeconomic factors. Methods: : This study recruited functionally independent male older adults from the Japan Gerontological Evaluation Study. Participants answered self-reported questionnaires mailed in 2013, followed up to 2016. Participants with COPD were screened as those with higher scores than the upper quantile of the modified International Primary Care Airway Group questionnaire. Regarding individual socioeconomic factors, educational attainment, household equivalized income, living arrangements, and social participation was assessed. The Cox proportional hazards model was applied to examine the association between screened COPD and mortality. Results: : Data of 6,662 male older adults were analyzed (mean age [standard deviation]: 73.0 [5.8] years). During the observation periods, 394 deaths (5.9%) occurred. Screened COPD was associated with an increased mortality risk, even after adjusting for socioeconomic factors (hazard ratio, 1.56; 95% confidence interval, 1.25-1.94). In the stratified analysis among current smokers, the mortality risk of screened COPD was high in those with lower education, higher income, living alone, and less social participation. Conclusions: : Those with screened COPD had an increased mortality risk, even after adjusting for socioeconomic factors. The risk was higher among those with lower education and less social relationships. Detection and treatment of COPD should be performed considering individual socioeconomic backgrounds.