BackgroundPreserved ratio impaired spirometry(PRISm) is considered to be a precursor of COPD. The purpose of our study is to investigate the prevalence and risk factors of PRISm in high-altitude areas
As part of the China National Health Survey, the objective of this study was to explore the prevalence, patterns, and influencing factors of smoking, and understand reasons for smoking cessation among
*Adjustments were made for age, marital status, education, employment and rural/urban residence. †Adjusted RII could not be obtained due to the reduced number of smokers within some of the categories
