Asthma–chronic obstructive pulmonary disease overlap in China: prevalence, associated factors and comorbidities in middle-aged and older adults

Abstract

Background

Asthma–COPD overlap (ACO) is a persistent airflow limitation with features of both asthma and chronic obstructive pulmonary disease (COPD). No studies have explored the prevalence of ACO at the national level in China.

Objective

In this study, we aimed to estimate the prevalence of ACO and to assess the associated factors and comorbidities of ACO in middle-aged and older Chinese.

Methodology

Participants aged 45 years and over in a nationally representative investigation – the China Health and Retirement Longitudinal Study (CHARLS) in 2011 – were included. ACO was defined as a dual self-reported physician diagnosis of asthma and COPD. The prevalence of ACO was demonstrated across different characteristic groups. The potentially associated factors and comorbidities were examined by logistic regressions.

Results

The prevalence of ACO was 2.22% in general middle-aged and older Chinese. The relative prevalence of ACO to asthma was 62.53% and that to COPD was 21.99%. Older age (≥70 years), Northwest China residence, smoking (former and current) and former alcohol drinking were associated with a higher risk of ACO. Comorbidities of ACO included stomach or other digestive disease, kidney disease, cardiovascular disease, and arthritis or rheumatism.

Conclusions

ACO was a prevalent condition in middle-aged and older Chinese. Better management and more research on ACO are needed.

Keywords:

• Asthma–chronic obstructive pulmonary disease overlap
• prevalence
• epidemiology
• survey

Transparency

Declaration of funding

None to disclose.

Declaration of financial/other relationships

No potential conflict of interest was reported by the authors.

Acknowledgements

All authors thank the China Health and Retirement Longitudinal Study (CHARLS) for providing data. We are grateful for those who designed, conducted and participated in this study.

Data availability statement

The data that support the findings of this study are openly available in the China Health and Retirement Longitudinal Study at http://charls.pku.edu.cn/en.