[Analysis of the trend and spatial clustering of gastric cancer deaths in Shandong Province from 1970 to 2013].

ABSTRACT

Objective: To investigate the distribution characteristics and trends of mortality and spatial aggregation of gastric cancer in Shandong Province from 1970 to 2013. Methods: The mortality data of gastric cancer from 1970 to 1974, 1990 to 1992 and 2004 to 2005 were collected from the first, second and third retrospective sampling survey of causes of death in Shandong Province, respectively. The mortality data of gastric cancer from 2011 to 2013 were collected from the all-cause surveillance data of Shandong Province. The crude mortality rate and age-standardized mortality rate were used to describe the death level of gastric cancer. The age-standardized mortality rate of Shandong Province was calculated based on Segi's world standard population, and the age-standardized mortality rate of counties (cities and districts) was calculated based on the Chinese population in 1964.The factors influencing the difference of gastric cancer mortality in different periods were decomposed by using the method of differential decomposition of mortality, and the contributions of population and non-population factors in different periods were estimated.Using ArcGIS 10.2 software, the death level of gastric cancer in different counties (cities and districts) in Shandong province from 1970 to 1974 and 2011 to 2013 were visualized. DeoDa 1.12 software was used for global and local spatial autocorrelation analysis. Results: The crude death rate and age-standardized death rate of gastric cancer in Shandong province increased firstly and then decreased during 1970-2013, and the crude death rate of gastric cancer increased from 18.33/100 000 in 1970-1974 to 28.51/100 000 in 2011-2013. Segi's age-standardized mortality rate for gastric cancer decreased from 20.94 per 100 000 in 1970-1974 to 18.17 per 100 000 in 2011-2013.From 1990 to 1992, from 2004 to 2005 and from 2011 to 2013, the contribution value of non-population factors to the increase of crude gc mortality was 95.59%, 48.45% and -20.57%, respectively, showing a continuous downward trend. The Moran's I index of crude mortality of gastric cancer in Shandong province from 1970 to 1974 and from 2011 to 2013 were 0.77 and 0.57, respectively, and the Moran's I index of age-normalized mortality was 0.75 and 0.44, respectively. Local autocorrelation analysis showed that there were 31 and 19 high aged-mortality areas of gastric cancer in 1970-1974 and 2011-2013 respectively, and 7 overlapping counties (cities and districts), 6 of which were located in Jiaodong area. Conclusion: The crude mortality and age-standardized mortality of gastric cancer in Shandong province increased first and then decreased from 1970 to 2013, and the distribution of gastric cancer mortality had obvious spatial aggregation and changed with time.