Differences in risk factors largely shaped the changes in COPD patterns between China and high socio-economic index (SDI) countries. According to a recent study published in PubMed, the researchers from the School of Public Health, Li Ka Shing Faculty of Medicine, The University of Hong Kong, analysed differences  in age-standardised incidence and mortality rates for COPD between China and high SDI countries from the Global Burden of Disease Study 2017. The researchers pointed out that smoking was the leading attributable risk factor followed by ambient air pollution, with higher rankings for occupational risks in China than in high SDI countries. The other competing risks such as ischemic heart disease also varied between settings contributing to the mortality rate of China.