Study On The Incidence Tendency Of Stroke, Coronary Heart Disease And Hypertension And The Population Aging Tendency In Dalian From 1991 To 2005

Objective: The incidence rates and prevalence rates of chronic non- communicable diseases are ascending yearly along with economic development, improvement of living standard and accelerating trends of industrialization, urbanization and population aging. Cardiovascular and cerebrovascular diseases such as stroke , coronary heart disease and hypertension have been even more threatening than ever to human health. Chronic diseases affected by multiple risk factors are related to population aging besides life style, behavior habit, hereditary factors and environ- mental factors. It is important to explain incidence fluctuation of chronic diseases by quantitative analysis of demographic factors when our country has already been in the aged society. This study was carried out based on the incidence data of stroke, coronary heart disease and hypertension in Dalian from 1991 to 2005.By comparing the incidence of these diseases in different age populations and also by analyzing the relationship between the incidence tendency of chronic diseases and the aging tendency of population quantitatively, the study aimed to explore the effect on incidence fluctuation caused by demographic factor and to provide scientific evidence for prevention and control of these diseases.Methods: The data of chronic diseases incidences were from annual chronic diseases reports by CDC in Dalian .The information of population was from Dalian Public Security Bureau .Calculate the incidence rates of stroke, coronary heart disease and hypertension yearly. Analyze the incidence fluctuating tendency and population aging tendency by linear regression. And analyze the effect on incidence fluctuation caused by population aging quantitatively by comparing the regression equation of incidence rates-time with the regression equation of aged population percents-time. SPSS was used to analyze the data.Results: The incidence rates of stroke, coronary heart disease and hypertension in total population, younger than 65y population and aged population were all ascending yearly in Dalian from 1991 to 2005. The average annual growth rates of stroke in three different populations were 11.3%,7.7%,9.6% respectively and there were no statistical significant difference between these rates. The average annual growth rates of coronary heart disease in three different populations were13.7% , 8.5% , 13.6% respectively and there were no statistical significant difference between total population and aged population and between aged population and younger than 65y population. Meanwhile the average annual growth rates of coronary heart disease in younger than 65y population was lower than that of total population. The average annual growth rates of hypertension in three different populations were 10.8 % ,6.2 % ,11.5 % respectively and there were no statistical significant difference between these rates. The aged population percents in five districts of Dalian were also ascending yearly from 6.6 in 1991 to 11.9 in 2005 with the average annual growth rates of 4.2%(P=0.000). The average annual growth rate of aged population percents was lower than that of stroke, coronary heart disease and hypertension in total population and it only accounted respectively for 37%,31%and 39% of the average annual growth rates related to stroke, coronary heart disease and hypertension in total population.Conclusions: The incidence rates of stroke, coronary heart disease and hypertension in total population, younger than 65y population and aged population were all ascending yearly in Dalian from 1991 to 2005. The average annual growth rates of the three diseases were no statistical significant difference between younger than 65y population and aged population. Hence cardiovascular and cerebrovascular diseases are posing a great threat not only to aged population but also to younger than 65y population. The aged population percents in five districts of Dalian were also ascending yearly from 1991 to 2005. Dalian has been in the aged society since 1993. The increase of the incidence of cardiovascular and cerebrovascular diseases can not be explained entirely by population ageing, instead, non- demographic factors played a rather primary role in it. Therefore to control non- demographic factors should be the key measure to prevent the chronic diseases.