The Chinese Population Health and Multimorbidity Study (CPHMS; initially named China Pulmonary Health Study, CPHS) was a large-scale epidemiological survey designed to investigate the pulmonary health of Chinese adults aged 20 years or older leveraging a multistage stratified sampling scheme between 2011 and 2014 in mainland China. Briefly, a total number of 57,779 local residents were recruited from 10 representative provinces and municipalities and were invited to participate in the study. A final number of 50,991 adults who met the major inclusion criteria could be considered in further analyses.

In order to investigate the changes of pulmonary health and disease status (e.g. occurrence and development of chronic respiratory diseases and other important relevant multimorbidities, lung function indices, etc.) and corresponding impact factors in the CPHMS study population, we plan to initiate the first round of follow-up investigation between 2025 and 2027 (planned) , i.e. more than 10 years after the baseline survey.

Inclusion Criteria:

• (1) the individuals who participated in the CPHMS baseline survey;
• (2) their ID number and phone number are available;
• (3) sign the informed consent.

Exclusion Criteria:

• (1) incapable of taking pre- and post-bronchodilator spirometry tests;
• (2) request to withdraw the informed consent;
• (3) terminate due to medical or ethical considerations judged by the investigators and/or ethics committee.

A total number of 50,991 adults aged 20 years or older from 10 representative provinces and municipalities of China participated in the CPHMS baseline survey between 2011 and 2014. In the follow-up investigation, ideally all the baseline participants should be contacted.