Impact of the POPulation Medicine Multimorbidity Intervention in Xishui County (POPMIX) on people at high risk for COPD who smoke: protocol for the POPMIX-Smoking cluster randomised controlled trial

Introduction Tobacco use is a major contributor to the burden of chronic obstructive pulmonary disease (COPD) and other non-communicable diseases in China. People at high risk for COPD who smoke, particularly those with pre-existing chronic conditions, often remain underserved by conventional smoking cessation programmes.

Population medicine offers a promising framework for proactively identifying high-burden diseases, managing multimorbidity and prioritising interventions for vulnerable populations. Methods and analysis This protocol describes a stratified, two-arm cluster randomised controlled trial (Population Medicine Multimorbidity Intervention in Xishui County-Smoking) being conducted in Xishui County, a rural area of Guizhou Province, China.

A total of 26 townships were stratified by population size and randomly assigned in a 1:1 ratio to receive either a multicomponent intervention or usual care. Eligible participants were individuals aged 35 years or older who smoked and were at high risk for COPD as identified by the COPD Screening Questionnaire.