Since 2000, substantial funds have been invested by the Sichuan government to improve maternal and child health in the minority areas[17]. Sichuan has made significant progress in improving the survival rate of children. During the study period, the mortality rate of children under the age of 5 years in Sichuan Province decreased by 51.2% (from 16.9‰ to 8.26‰)[21, 22].The study showed that PU5MR declined in Sichuan Province from 2010 to 2017, especially in the minority counties. However, the RR the relative risk of pneumonia mortality of minority to non-minority communities only decreased from a high of a seven-fold to a low of a five-fold difference between 2010 to 2017, peaking in 2013 with its low point in 2014, and in fact increased over the last two years of observationRRof pneumonia mortality of minority to non-minority counties only decreased from a high of a seven-fold to a low of a five-fold difference between 2010 to 2017 and in fact increased over the last two years of observation. The minority counties remain at orders of magnitude difference in pneumonia mortality rates, relative risk of pneumonia mortality of minority to non-minority communities only decreased from a high of a seven-fold to a low of a five-fold difference between 2010 to 2017, peaking in 2013 with its low point in 2014, and in fact increased over the last two years of observation.and there was still a large gap between the minority and nonminority counties.
The decline of PU5MR was due to social and economic growth, an increase in health and human resources, the improvement of child nutrition, and an increase access to child healthcare [17, 18]. The medical service capacity, health infrastructure, and availability of medical and health services in the minority regions lagged far behind that of the nonminority regions[23]. In addition, more than half of the health input was borne by the county governments, and it was difficult for the minority counties with lower economic conditions to invest in full and on time[24, 25]. Both the PU5MR and the proportion of pneumonia deaths to total deaths in the minority counties were still higher than those in the nonminority counties. Therefore, it is important to increase investment in the minority regions and promote more balanced development. The government needs to give preference to the minority counties in terms of financial, medical and health equipment, and health and human resources investment.
The current study likewise shows that the proportion of pneumonia deaths to total deaths decreased with time in the minority counties but not in the nonminority counties or the whole province. Children are at a greater risk than adults from the many adverse health effects of air pollution. Their bodies, especially their lungs, are rapidly developing and therefore are more vulnerable to inflammation and other damages caused by pollutants [26]. Due to high humidity and weak wind, the ambient air pollution in the Sichuan basin has become very serious in recent years, especially in the urban areas [27, 28]. More than 90% of the nonminority counties are located in the urban areas. The rise of the proportion of pneumonia deaths to total deaths in the nonminority counties can be partly interpreted by this outcome. The relationship between ambient air pollution and the morbidity and mortality of child pneumonia and the relevant countermeasures should be further studied.
In the minority and nonminority counties, PU5MR decreased within each age group, including the 0-28 days age group, 29 days-11 months age group, and 12-59 months age group. The decline in childhood was the most dramatic among the three age groups. This result may be related to the implementation of some policy measures, including the basic public health services, the major public health services and the introduction of pneumococcal 7-Valent conjugate vaccine (PCV7). Since 2009, the implementation of the basic and major public health services project has increased the percentage of systematic care for children and improved people’s health knowledge[29]. After a series of effective strategies for neonates between 1996 and 2013, such as in-hospital delivery and neonatal family visits reported by He et al.[3], the effect of the follow-up measures may be more obvious in childhood. The dramatic decline in childhood can also be partly explained by a lag phase for the indirect effects of PCV7 observed by Steens A et al. in 2013[30]. Although the mortality rate decreased, disparities in pneumonia-specific U5MR between the minority and nonminority regions still exist. The pneumonia-specific U5MR in the minority regions was significantly higher than that of the nonminority regions in each age group, and it was highest in the minority counties. There are ethnic differences in pneumonia mortality rates in many developed countries, including Australia[31], South Africa[32] and the United States[33]. Particularly, compared with neonates, the RR of postneonates in the minority counties has increased from 2010 to 2017. The highest mortality rate existed in postneonates of the minority regions. Pneumonia-specific U5MR of postneonates in the minority regions was 179.2 per 100,000, which was still higher than that of 162.8 per 100,000 in 2014-2015 of mainland China, let alone Central and Eastern China[8]. Therefore, more attention needs to be paid to postneonates in the minority counties.
Access to health services in developing countries is affected by many factors, including geographic accessibility, availability, financial accessibility, and acceptability [34]. According to the Sichuan Health and Family Planning Statistical Yearbook of 2016[22], the accessibility of healthcare sources is worse in the minority areas than in the nonminority areas. First, the minority regions are sparsely populated, and the area of the minority regions accounts for more than half of Sichuan Province, while the healthcare facilities accounts for only 19.3% of the total. Second, the number and educational and professional skill levels of the health service providers in the minority regions are poorer than those the nonminority regions and cannot meet the demands of the people living there. From the perspective of the family and the individual, the low household income and low education level of the minorities are both important factors affecting the accessibility to medical service. The number of children untreated before death in the minority regions accounted for 47.2% of the total deaths in 2017, and no downward trend was found in the present study. Meanwhile, the proportion of children treated in the provincial/municipal level hospitals before death was still relatively low in the minority regions.
Although Sichuan achieved the Millennium Development Goal (MDG4) in 2006, the proportion of pneumonia-specific deaths to total under-five-years-of-age deaths was 15.5% in 2017, with a particularly high proportion in the minority regions (28.9%). The Global Goals For Sustainable Development clearly state the goal of eliminating avoidable deaths of newborns and children under five years of age by 2030[35]. It has been shown that a comprehensive set of interventions can effectively prevent and reduce childhood pneumonia[36]. First, exclusive breastfeeding for the first six months, appropriate supplementary feeding and supplementation of vitamin A were all recognized as helping to decrease the incidence and reduce the severity of pneumonia[36]. Therefore, a series of interventions combining individual level and group level health promotion should be implemented (e.g., improving the mother's education degree, enhancing health education, implementing a nutrition enhancement program). Second, vaccines against Haemophilus influenzae type b(Hib) and Streptococcus pneumonia(S. pneumoniae) should be included in the routine childhood immunization program. As the two most frequent childhood pneumonia bacteria, vaccines against Hib and S. pneumoniae could decrease the incidence by 22-34% for Hib and 23-35% for S. pneumoniae[37]. Third, the fairness and availability within Sichuan Province, especially in the minority counties, should be improved as soon as possible, and a convenient medical network according to the regional characteristics of minority regions needs to be studied and established to improve the treatment of children who are ill from pneumonia. Last, ambient air pollution control should be taken into account in the prevention of childhood pneumonia.
There are some limitations to this study. Since the data were collected from DRSMCH in Sichuan Province and based on the three-level administration network (urban, community-district-city; rural, village-township-county), it is difficult to obtain an accurate diagnosis of pneumonia in children. However, we have taken a series of measures to ensure the accuracy of diagnosis and the quality of the data. First, ICD codes were used for reporting the causes of deaths, allowing the staff to obtain more information about child deaths[18]. Second, the staff working in the reporting system were trained yearly for death classification and ICD coding. Third, the provincial experts in epidemiology and pediatrics conducted quarterly examinations and confirmations of the causes of death. Another limitation to this study is that demographic data were not collected, such as family income per capita, parents’ educational level, and distance from a patient’s home to the medical institutions, which made it impossible to analyze in depth the causes of the PU5MR.