Wang N, Cong S, Fan J, et al. - By performing a nationwide cross-sectional analysis including 66,752 adults across mainland China, researchers determined the variations in the prevalence of COPD at city-level as well as explored the relative significance of COPD associated risk factors in mainland China. Via spatial scan statistics, they ascertained spatial clusters with a significantly higher prevalence of COPD. They noted that in parts of Sichuan, Gansu, and Shaanxi, etc, the three spatial clusters with the highest COPD prevalence were located. As demonstrated by CART (classification and regression tree), the most crucial factor related to COPD in the overall population was advanced age (≥ 60 years), followed by smoking. In the north, northeast, and southwest of China, PM_2.5 was identified as an essential related risk factor for COPD. A shift in the spatial cluster with the highest prevalence to most of Sichuan, Gansu, Qinghai, and Ningxia, etc, was evident following adjustment for age and smoking. The development of tailored interventions for COPD in China would be aided by spatial clusters of COPD at the city level as well as regionally distinct crucial risk factors for COPD. The shift noted in the spatial clusters of COPD following adjustment for the main risk factors is suggestive of the existence of other potential risk factors for the remaining clusters.