| Background and ObjectiveWith social-economic development of China, changes of the living environment and lifestyle and the intensification of the aging population, high incidence and mortality of chronic diseases, especially cardiovascular and cerebrovascular diseases, have been the heavy burden for the society. The prevalence of ischemic cardiovascular disease (ICVD) in the elderly, epidemiological studies showed that the age of onset tended to be younger in recent years. It is urgent that further strategies and measures should be taken to prevent ischemic cardiovascular disease. This study aims to construct ICVD risk assessment through multilevel analysis based on the population from different districts of Henan province, hence to provide data support and theoretical evidence for ICVD prevention and policy interventions.MethodsA multistage random sampling cross-sectional survey stratified by age and gender was designed among Henan province who are not younger than 15 years old. The mainly used methods for data analysis include fixed logistic regression, multi factor descending dimension method (MDR) and two level logistic regression for ICVD risk assessment model.19,000 participants are from 10 cities/counties in Henan Provinces. The field investigation formated face to face questionnaire interview and examination on-site body measurements. The contents of the questionnaire include population characteristics, life behavior habits of the recent year, ICVD history and related family illness history. Examination contains items of blood pressure measurements, body mass assessment, etc.Calibration and evaluation of digital blood pressure device:Digital blood pressure device (Omron HBP-1300), which was utilized all through for the participants, are calibrated against the mercury blood pressure monitor. Two surveyors used blind method recording the measurement results. The individuals participated in the quality control of blood pressure measurement were divided into two groups, one for the accuracy test of blood pressure measurement (n=72), and the other for the evaluation of validation of the blood pressure (n=106). The reliability of the blood pressure values was evaluated by intra-group correlation coefficient (ICC). The differences of the accuracy between the two blood pressure devices were tested by paired sample t test. Linear regression model was performed to calibrate the deviation of systolic blood pressure. Repeated measurement analysis of variance was conducted to assess the effect of time and population characteristics on blood pressure. The effect of quality control was also verified by the standard of AAMI (The Advancement Of Medical Instrumentation) and BHS (British Hypertension Society).Statistical description and univariate analysis:The numerical variables were tested for normality. For variables in line with the normal distribution, a mean (standard variance) was described; if not, the variables were conversed. If the variables were in non-normal distribution, they were described with a median (range) and the groups were compared using non parametric test; The groups of classification variables were compared using chi square test.Multivariate analysis and model construction:Logistic regression analysis was used to analyze the risk factors of the ischemic cardiovascular disease. The multifactor dimensionality reduction was used to deal with the interaction among varibles, and the multilevel model of ICVD was constructed based on both the districts’ and the individuals’ information.ResultsTotal of valid 18943 participants were included in the study, of which 7966 men (42.08%) and 10977 women (57.92%). The gender ratio of male and female was 0.73:1. The mean age was averaged 52.18±16.78 (years), ranging from 15 to 98 years old. The average age was 51.37±17.10 (years) and 52.77±16.53 (years) for men and women, respectively. There were statistically significant difference in the number of men and women (t=-5.618, P< 0.0001).The study also revealed that the intake amount of potato, meat, poultry, eggs, milk, and fruit in hypertensive subjects were significant higher than those in non-hypertensive population; Similarly, significant differences of cooking oil and salt consumption were also found between hypertensive and non hypertensive individuals (P<0.05); However, no significant differences are found in the consumption of animal fat between the two groups (P> 0.05); Physical activity and exercise were negatively related to blood pressure(P<0.05); The factors such as body weight, waist circumference, basal metabolic rate, body fat, visceral fat were also significant difference between two groups (P<0.05); Hypertension was associated with the first-degree family history of hypertension, hyperlipidemia and stroke (P<0.05). Ischemic cardiovascular diseases was linked to the family history of hypertension and stroke (P<0.05); The family history of diabetes and coronary heart disease (CHD) were not found to be related with hypertension and ICVD. Hypertension could increase the risk of ICVD, especially cerebrovascular accident (CVA) (OR=7.54,95%CI=6.59-8.64); The hypertensives had 2.38(95%CI=1.89-3.00) times higher risk of induced myocardial infarction (MI) and 3.90 (95%CI= 1.89-8.04) times of CVA and/or MI than non-hypertensives.The optimal model obtained by MDR analysis was hypertension, age, education level, occupation, history of smoking and dietary amount. The average accuracy of the training set was 0.79, and the consistency of CV was 10/10. The eleven-order model of hypertension is better than the ICVD model. The specificity and sensitivity of model prediction in training set were 0.88 and 0.98, respectively. The consistency between the training set and the test set was strong (Kappa=0.74). The goodness of fit of the multilevel model proved to be better than that of traditional logistic regression.Diastolic blood pressure measured by digital blood pressure device ((Omron HBP-1300) were reliable. Meanwhile, systolic blood pressure (SBP) can be corrected by the equation of (MSBPB=0.803* MSBPA+19.592). The equation was validated through testing population and passed both the AAMI standards and ESH protocols.ConclusionsA two-level ICVD risk assessment model were constructed, which constrated on the effect of higher level (area, altitude geographical environment, and the number of doctors/per 10,000) and on risk profiles of individual level (i.e. smoking, moderate intensity exercise, salt intake, hypertension family history, body mass index, age, education level, marital status, drinking). Multilevel model, compared with traditional risk prediction model, has certain advantages in evaluating and predicting the risk of ischemic cardiovascular disease. High-risk population screening strategy based on the multilevel model combined with health education and health promotion measures has great potential application value in the primary prevention of ischemic cardiovascular disease. |
PDF Full Text Request