Evaluating an intervention for neural tube defects in coal mining cites in China: a temporal and spatial analysis.

BACKGROUND: Neural tube defects (NTDs) are congenital birth defects of the central nervous system that affect 0.5-2 per 1000 pregnancies worldwide. Therefore effective interventions for birth defects, especially NTDs, are very important. METHODS: Yuanping City is a coal mining city in Shanxi Province, China, with a high incidence of NTDs. This study evaluates the effects of NTD interventions in this city after adjusting for covariates that characterize the native environment. The number of NTD cases and births for the 18 towns in Yuanping City from 2007 to 2014 were included in the study. A shared-component zero-inflated Poisson regression was applied to analyse the temporal-spatial variance among the incidence rates of NTDs in Yuanping City before and after the interventions. RESULTS: The results showed that existing interventions to mitigate birth defects, such as folic acid supplementation, reduced the incidence of NTDs by 53.5% in coal mining areas in Yuanping City. However, the NTD risk in areas near coal mines, especially unrestored coal mines, was still high, even after the intervention. CONCLUSIONS: The government should focus on health hazards related to mining and agricultural production and should provide education and resources to reduce environmental exposure. Reducing environmental risks should be regarded as an early intervention strategy to mitigate birth defects.

Application of sandwich spatial estimation method in cancer mapping: A case study for breast cancer mortality in the Chinese mainland, 2005.

High-accuracy spatial distribution estimation is crucial for cancer prevention and control. Due to their complicated pathogenic factors, the distributions of many cancers' mortalities appear blocky, and spatial heterogeneity is common. However, most of the commonly used cancer mapping methods are based on spatial autocorrelation theory. Sandwich estimation is a new method based on spatial heterogeneity theory. A modified sandwich estimation method suitable for the estimation of cancer mortality distribution is proposed in this study. The variances of cancer mortality data are used to fuse sandwich estimation results from various auxiliary variables, the feasibility of which in estimating cancer mortality distributions is explained theoretically. The breast cancer (BC) mortality of the Chinese mainland in 2005 was taken as a case, and the accuracy of the modified sandwich estimation method was compared with that of the Hierarchical Bayesian (HB), the Co-Kriging (CK) and the Ordinary Kriging (OK) methods. The accuracy of the modified sandwich estimation method was better than the HB, the CK and the OK methods, and the estimation result from the modified sandwich estimation method was more likely to be acceptable. Therefore, this study represents an attempt to apply the sandwich estimation method to the estimation of cancer mortality distributions with strong spatial heterogeneity, which holds great potential for further application.

Trends in geographical disparities for cervical cancer mortality in China from 1973 to 2013: a subnational spatio-temporal study.

OBJECTIVE: This study was designed to explore the time trends in geographical variations of cervical cancer mortality in mainland China over the period 1973 to 2013, to provide subnational spatio-temporal patterns for targeted promotion of human papillomavirus vaccine in China. METHODS: Data were extracted from three national retrospective death surveys and cancer registry. The rate ratio (RR) was estimated for the aggregated data for seven geographical regions using generalized linear models to evaluate time trends in geographical disparities of cervical cancer mortality. RESULTS: There was a significant decrease in cervical cancer mortality in China from 1973-1975 to 2004-2005, but leveled off thereafter to 2011-2013. Compared to the period 1973-1975 the RR for the three last time periods were 0.33 [95% confidence interval (95% CI): 0.30-0.37] for 1990-1992, 0.21 (95% CI: 0.19-0.24) for 2004-2005 and 0.24 (95% CI: 0.22-0.26) for 2011-2013. Females living in the Northwest China and Central China have a high risk of mortality from cervical cancer compared to the nationwide, with the RR being 2.09 (95% CI: 1.83-2.38) and 1.26 (95% CI: 1.11-1.44) respectively, while the RRs for South China, Northeast China and Southwest China were below 1.00, indicating the lower death risk. Despite the mortality rate had increased slightly from 2004 to 2013, there was an encouraging sign that the geographical disparities in cervical cancer mortality had gradually narrowed over time across China. CONCLUSIONS: Although cervical cancer mortality in China has reduced to very low levels, the high risk of cervical cancer in Northwest China and Central China is still noteworthy. Public health policies including the promotion of vaccine should be targeted to further reduction of geographical disparities in cervical cancer mortality.

Temporal and Spatial Analysis of Neural Tube Defects and Detection of Geographical Factors in Shanxi Province, China.

BACKGROUND: Neural tube defects (NTDs) are congenital birth defects that occur in the central nervous system, and they have the highest incidence among all birth defects. Shanxi Province in China has the world's highest rate of NTDs. Since the 1990s, China's government has worked on many birth defect prevention programs to reduce the occurrence of NTDs, such as pregnancy planning, health education, genetic counseling, antenatal ultrasonography and serological screening. However, the rate of NTDs in Shanxi Province is still higher than the world's average morbidity rate after intervention. In addition, Shanxi Province has abundant coal reserves, and is the largest coal production province in China. The objectives of this study are to determine the temporal and spatial variation of the NTD rate in rural areas of Shanxi Province, China, and identify geographical environmental factors that were associated with NTDs in the risk area. METHODS: In this study, Heshun County and Yuanping County in Shanxi Province, which have high incidence of NTDs, were selected as the study areas. Two paired sample T test was used to analyze the changes in the risk of NTDs from the time dimension. Ripley's k function and spatial filtering were combined with geographic information system (GIS) software to study the changes in the risk of NTDs from the spatial dimension. In addition, geographical detectors were used to identify the risk geographical environmental factors of NTDs in the study areas, especially the areas close to the coal sites and main roads. RESULTS: In both Heshun County and Yuanping County, the incidence of NTDs was significantly (P<0.05) reduced after intervention. The results from spatial analysis showed that significant spatial heterogeneity existed in both counties. NTD clusters were still identified in areas close to coal sites and main roads after interventions. This study also revealed that the elevation, fault and soil types always had a larger influence on the incidence of NTDs in our study areas. In addition, distance to the river was a risk factor of NTDs in areas close to the coal sites and main roads. CONCLUSION: The existing interventions may have played an important role to reduce the incidence of NTDs. However, there is still spatial heterogeneity in both counties after using the traditional intervention methods. The government needs to take more measures to strengthen the environmental restoration to prevent the occurrence of NTDs, especially those areas close to coal sites and main roads. The outcome of this research provides an important theoretical basis and technical support for the government to prevent the occurrence of NTDs.