| On the basis of the world health organization(WHO)data,about 8 million people died because of all sorts of cancers;about 70%of all cancer deaths occur in low and middle income countries each year.As two common malignant tumors,liver cancer and esophageal cancer make great contribution to health and death worldwide.There is great geographical distribution variation of incidence and mortality rate on global scale or on different region levels.Disease mapping is a major branch of epidemiology,which is usually used to discover spatial pattern of diseases,aimed to identify area of elevated risks.The purpose of this study is to describe mortality of malignant tumor in Shandong Province on the basis of all cause death registry dataset,evaluate burden of disease,detect the spatial pattern,and determine geographical clusters focusing on liver cancer and esophageal cancer.Liver and esophageal cancer mortality cases from the Shandong Tumor Registry from 2011-2013 were used for illustrative purpose.Crude mortality rate,age adjusted mortality rate were calculated by sex,region(ubran/rural area),age groups on county level;DALY was calculated to evaluate burden of disease;standardized mortality ratio and relative risk modeled by Bayes BYM model were calculated;global and local Moran's I were adopted to assess the spatial autocorrelation;clusters of elevated rates were identified using a spatial scan statistic;Bayesian shared component model was used to joint disease mapping.Results:1 Liver cancer(1)Result of epidemiology analysis:?A total of 85688 mortality cases occurred during 2011-2013 in Shandong Province,ranked 2 in malignant tumor cause of death after lung cancer,accounted for 17.00%in all malignant tumor deaths and 3.85 in all cause deaths.?The mortality rate of males and females were 43.03/100,000 and 16.31/100,000 respectively.The mortality rate of males was 2.67 times of that of females.?The mortality rate in rural areas(25.42/100,000)was higher than in urban areas(32.21/100,000).?The health burden on the rural and urban due to liver cancer was 4.50 and 3.67 per 1000 respectively,demonstrated that the burden on the rural resident was heavier than that on urban.(2)Result of spatial analysis:?There were five counties whose SMR was higher than 1.5 including Qingyun of Deizhou city,Qixia,Laiyang,Haiyang,Fushan of Yantai city.?Result of BYM model showed that the spatial structured random effect is the major cause of spatial heterogeneity.?Global Moran's I=0.59,P<0.001 indicated the strong spatial autocorrelation.Result of local Moran's I showed that the high-high areas were distributed in Yantai city,Qingdao city and Weihai city.?Spatial scan statistic showed that there were 21 significant clusters of elevated risk,including 1 most likely cluster and 20 secondly likely clusters.The most likely cluster consist of Haiyang and Muping of Yantai city and Rushan of Weihai city,the RR was 1.95(P<0.01).2 Esophageal cancer(1)Result of descriptive epidemiology analysis:?A total of 45805 mortality cases occurred during 2011-2013 in Shandong Province,ranked 4 in malignant tumor cause of death,accounted for 9.08%in all malignant tumor deaths and 1.91 in all cause deaths.? The mortality rate of males and females were 23.76/100,000 and 7.59/100,000 respectively.The mortality rate of males was 2.99 times of that of females.?The mortality rate in rural areas(18.16/100,000)was higher than in urban areas(12.66/100,000).?The health burden on the rural and urban due to liver cancer was 2.16 and 1.54 per 1000 respectively,which demonstrated that the burden on the rural resident was heavier than that on urban.(2)Result of spatial analysis:?There were five counties whose SMR was higher than 1.5 including Dongping,Ningyang,Feicheng of Taian city;Wenshang,Yanzhou of Jining city;Pingyin,Changing of Jinan city;Tengzhou of Zaozhuang;Lanshan ofRizhao city;Kenli of Dongying city;Dongming of Heze city.?Result of BYM model showed that the spatial structured random effect is the leading cause of spatial heterogeneity.? Global Moran's I-0.50,P<0.001 indicated the strong spatial autocorrelation.Result of Local Moran's I showed that the high-high areas were distributed inDaiyue,Ningyang,Dongping,Xintai,Feicheng of Taian city;Wenshang,Sishui,Liangshan,Qufu,Yanzhou of Jining city;Changing,Pingyin of Jinan city;Dong'a,Yanggu of Liaocheng city.?Spatial scan statistic showed that there were 19 significant clusters of elevated risk,including 1 most likely cluster and 18 secondly likely clusters.The most likely cluster was Ningyang of Taian city,the RR was 4.57(P<0.01).3 Joint disease mapping:the high value of shared RR of liver cancer and gastric cancer clustered in east and center of Shandong province;the high value of specific RR of liver cancer clustered in east,southeast and south of Shandong province while that of gastric cancer clustered in center and south of Shandong province.Conclusion:(1)The mortality rates of males were higher than that of females for both liver and esophageal cancer in Shandong province,showed significant spatial autocorrelation and had clusters of elevated risks,spatial structured random effect was the leading cause of spatial heterogeneity of mortality.(2)The spatial analysis by GIS is a method that is feasible and helpful in generating hypothesis and identifying areas for intervention.It could be necessary and important for public health policymakers to promote strategies for cancer control and management for infrastructure.Our study showed spatial analysis of cancer mortality rate and clustered pattern in the Shandong province from 2011 to 2013.Further studies are needed on the efficiency of GIS,not only to determine etiological agents of cancer but also to help policy makers in management of health promotion.(3)Bayes method and joint disease mapping play an important role in spatial analysis of disease.Therefore the approach should be widely used. |
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