关键词: 儿童死亡率, 5岁以下儿童, 死亡原因, 潜在寿命损失, 贫困, 云南

Abstract:
Background　In the last several decades，the Chinese Government has made substantial progress in reducing under-five mortality rate（U5MR），but the disparity in U5MR between urban and rural areas still exists. Objective　To identify the main causes of death and potential years of life lost among children under 5 years old across different regions of Yunnan Province from 2015 to 2019. Methods　According to the poverty headcount ratio in 2017，a total of 129 districts and counties in Yunnan were categorized into severely impoverished，poor，and non-poor areas. Data about reported death among children under 5 years old in these areas during 2015—2019 were collected，and described statistically using the mortality rate，proportion of deaths by cause，potential years of life lost，potential years of life lost rate，and average years of life lost. Poisson regression model was adopted to estimate the trend in U5MR and its 95%CI during 5 years for three types of areas. Chi-square test was chosen to analyze the changes in death places during 5 years. The data source came from "population death information registration management system" of "China Disease Control and prevention information system" of Yunnan Center for Disease Control and Prevention. Results　U5MR in Yunnan had decreased by -28.23% for 5 years，at -7.60% per year on average〔95%CI（-8.52%，-6.76%）〕. The same decline trends happened in severely impoverished areas｛-29.51% for 5 years，-6.95% per year on average〔95%CI（-8.51%，-5.45%）〕｝，poor areas｛-13.34% for 5 years，-3.15% per year on average〔95%CI（-4.59%，-1.69%）〕｝，and non-poor areas｛-42.66% for 5 years，-13.76% per year on average〔95%CI（-15.38%，-12.10%）〕｝. The majority of under-5 deaths took place at home in severely impoverished areas，but the proportion had reduced by year. By contrast，the majority of under-5 deaths took place at hospital in poor areas and non-poor areas，and the proportions had reduced by year as well. The differences in death places among children under 5 years old in poor areas were statistically significant across years （P<0.05）. The top three causes of death were birth trauma and asphyxia，lower respiratory tract infection，and congenital heart disease in both 2015 and 2019. Low birth weight and birth trauma and asphyxia caused the highest average years of life lost. Conclusion　In Yunnan Province，the reported mortality rate of children under 5 years old showed a significant decrease in all three regions with different levels of poverty. Given that the disparities in child health between poor and non-poor areas have remained，and the massive loss of life years have caused due to early death，substantial efforts are needed in future to strengthen the capacity to provide perinatal care and to end preventable deaths among children under 5 years old in those underdeveloped areas that have been lifted out of poverty currently.

Key words: Child mortality, Children under 5 years old, Cause of death, Potential years of life lost, Poverty, Yunnan