Dedefo Melkamu, Mwambi Henry, Fanta Sileshi, Assefa Nega
School of Mathematics, Statistics and Computer Science, University of KwaZulu-Natal, Pietermaritzburg.
Geospat Health. 2018 Nov 12;13(2). doi: 10.4081/gh.2018.681.
Cardiovascular diseases (CVDs) are the leading cause of death globally and the number one cause of death globally. Over 75% of CVD deaths take place in low- and middle-income countries. Hence, comprehensive information about the spatio-temporal distribution of mortality due to cardio vascular disease is of interest. We fitted different spatio-temporal models within Bayesian hierarchical framework allowing different space-time interaction for mortality mapping with integrated nested Laplace approximations to analyze mortality data extracted from the health and demographic surveillance system in Kersa District in Hararege, Oromia Region, Ethiopia. The result indicates that non-parametric time trends models perform better than linear models. Among proposed models, one with non-parametric trend, type II interaction and second order random walk but without unstructured time effect was found to perform best according to our experience and. simulation study. An application based on real data revealed that, mortality due to CVD increased during the study period, while administrative regions in northern and south-eastern part of the study area showed a significantly elevated risk. The study highlighted distinct spatiotemporal clusters of mortality due to CVD within the study area. The study is a preliminary assessment step in prioritizing areas for further and more comprehensive research raising questions to be addressed by detailed investigation. Underlying contributing factors need to be identified and accurately quantified.
心血管疾病(CVDs)是全球首要死因,也是全球死亡的头号原因。超过75%的心血管疾病死亡发生在低收入和中等收入国家。因此,了解心血管疾病死亡率的时空分布的全面信息很有意义。我们在贝叶斯分层框架内拟合了不同的时空模型,允许在死亡率映射中进行不同的时空交互,并采用集成嵌套拉普拉斯近似法来分析从埃塞俄比亚奥罗米亚州哈拉雷格市克尔萨区的健康与人口监测系统中提取的死亡率数据。结果表明,非参数时间趋势模型比线性模型表现更好。根据我们的经验和模拟研究,在所提出的模型中,一个具有非参数趋势、II型交互作用和二阶随机游走但无结构化时间效应的模型表现最佳。基于实际数据的应用表明,在研究期间,心血管疾病导致的死亡率有所上升,而研究区域北部和东南部的行政区显示出风险显著升高。该研究突出了研究区域内心血管疾病死亡率明显的时空聚集情况。该研究是在为进一步更全面的研究确定优先领域方面的初步评估步骤,提出了需要通过详细调查来解决的问题。需要确定并准确量化潜在的促成因素。