RESUMO
Objective To investigate the 6-year accumulative incidence rate of ischemic cardiovascular disease (ICVD) and its related risk factors. Methods Baseline population was all from an elderly population with members all born before 1-1,1938 and under health care programm.Data was recorded in a database of a hospital and baseline of subjects under research was aged ＞65years. People that had had ICVD at baseline were excluded. Risk factors under research would include: age at the baseline study, gender, body mass index, systolic blood pressure, serum cholesterol level, serum triglyceride level, serum high-density lipoprotein level, serum triglyceride level, serum apolipoprotein A1 level, history of diabetes mellitus and cigarette smoking etc. Single factor analysis was carried out using person-years as time of study, then calculating the person-year incidence and the accumulative incidence rate at different levels related to baseline risk factors.Multivariate analysis was under Cox Proportional Hazards Regression Model. Results Baseline population included 2271 elderly men, with the 6-year cumulative prevalence rate of ICVD as 23.56%, and the person-year prevalence rate was 45.41‰. Single factor analysis showed that the ICVD events positively related to variables which including systolic blood pressure, body mass index,serum cholesterol level and serum triglyceride level, serum apolipoprotein A1 level, status of diabetes mellitus and cigarette smoking. The ICVD events negatively related to variables as serum high-density lipoprotein levcl and serum creatinine level. Results of multivariate analysis showed that high systolic pressure, diabetes mellitus, serum creatinine level, Body Mass Index were the main risk factors. The serum high-density lipoprotein level served as the main protective factor. Conclusion The aged male population under health care programme was high in the ICVD prevalence rate, suggesting that programmes as controlling blood pressure, blood glucose, and increasing serum high-density lipoprotein levels were effective measures to decrease the ICVD events.
RESUMO
Objective To establish and verify the prediction model for ischemic cardiovascular disease(ICVD)among the elderly population who were under the current health care programs. Methods Statistical analysis on data from physical examination, hospitalization of the past years, from questionnaire and telephone interview was carried out in May, 2003. Data was from was randomly selected to generate both module group and verification group. Baseline data was induced to make the verification group into regression model of module group and to generate the predictive value. Distinguished ability with area under ROC curve and the predictive veracity were verified through comparing the predictive incidence rate and actual incidence rate of every deciles group by Hosmer- Lemeshow test. Predictive veracity of the prediction model at population level was verified through comparing the predictive 6-year incidence rates of ICVD with actual 6-year accumulative incidence rates of ICVD with error rate calculated. Results The samples included 2271 males over the age of 65 with 1817 people for modeling population and 454 for verified population.All of the samples were stratified into two layers to establish hierarchical Cox proportional hazard regression model, including one advanced age group(greater than or equal to 75 years old), and another elderly group(less than 75 years old). Data from the statically analysis showed that the risk factors in aged group were age, systolic blood pressure, serum creatinine level, fasting blood glucose level, while protective factor was high density lipoprotein; in advanced age group, the risk factors were body weight index, systolic blood pressure, serum total cholesterol level, serum creatinine level, fasting blood glucose level, while protective factor was HDL-C. The area under the ROC curve (AUC)and 95%CI were 0.723 and 0.687-0.759 respectively. Discriminating power was good. All individual predictive ICVD cumulative incidence and actual incidence were analyzed using Hosmer-Lemshow test, x 2=1.43, P=0.786, showing that the predictive veracity was good.Conclusion The stratified Cox Hazards Regression model was used to establish prediction model of the aged male population under a certain health care program. The common prediction factor of the two age groups were: systolic blood pressure, serum creatinine level, asting blood glucose level and HDL-C. Thc area under the ROWC curve of the verification group was 0.723, showing that the distinguished ability was good and the predict ability at the individual level and at the group level were also satisfactory. It was feasible to using Cox Proportional Hazards Regression Model for predicting the population groups.