ABSTRACT
To compare the designing effects (DE) among different complex sampling designing programs.Data from the ‘2002 Chinese Nutrition and Health Survey' was used as an example to generate the sampling population,and statistical simulation method was used to estimate the values of DEs from six complex sampling designing programs.It was found that the values of DEs varied among the six complex sampling designing programs.The values of the DEs were associated with the sample sizes in a positive way,with more sample stages and less stratified categories.Reduction of the numbers of sample stages and detailing stratified categories could decrease the DE values so as to improve the DE.
ABSTRACT
<p><b>OBJECTIVE</b>To describe the status and characteristics of under-reporting of death cases within national disease surveillance system (DSPs).</p><p><b>METHODS</b>Six villages (communities) were selected in each of the 161 counties of DSPs by multi-stage random cluster sampling methods, the information of resident from 2006 to 2008 was collected, and a survey of the under-reporting deaths cases was carried out which covered 6 422 667 people in all. The under-reporting rate was estimated by ages, genders and regions. The mortality was compared before and after the adjustment of the under-reporting rate.</p><p><b>RESULTS</b>The total crude rate of under-reporting of whole nation was 16.68% (6271/37 603), and after the adjustment by weight the rate was 17.44%; the under-reporting rate of urban areas was a bit lower than rural areas, which were 16.08% and 18.14% respectively (P < 0.01); the under-reporting rate of middle and west regions were higher than the east, which were 19.27%, 18.15% and 15.46% respectively (P < 0.01). The under-reporting rate of children of under-five years old was much higher than that of people of five and above-five years old, which were 34.95% and 16.90% respectively (P < 0.01). The gender difference was especially obvious in age group 0-4, for women 39.36% while 31.93% for men. After adjusted by under-reporting rate, the mortality rate of male raised from 6.38‰ to 7.74‰ and for female raised from 4.66‰ to 5.64‰. In the middle region, the mortality rate of male raised from 6.49‰ to 8.00‰ and for female raised from 4.59‰ to 5.73‰ after the adjustment. And the mortality rate of male in age group 0-4 raised from 2.48‰ to 3.64‰ and for female raised from 1.98‰ to 3.27‰. Of which in urban area, the mortality rate of male was much higher than female before the adjustment, which were 1.76‰ and 1.39‰ respectively; however, the mortality rate of male was a bit lower than female after the adjustment, which were 2.26‰ and 2.41‰ respectively. The mortality in male of five and above-five raised from 6.60‰ to 7.69‰ after the adjustment while in female raised from 4.80‰ to 5.77‰.</p><p><b>CONCLUSION</b>There are regional and age-group differences of the under-reporting rate of the National Disease Surveillance System. The gender differences mainly shows in age 0-4.</p>
Subject(s)
Adolescent , Adult , Aged , Child , Child, Preschool , Female , Humans , Infant , Infant, Newborn , Male , Middle Aged , Young Adult , China , Epidemiology , Disease Notification , Mortality , Population SurveillanceABSTRACT
<p><b>OBJECTIVE</b>To identify the relationship of body mass index (BMI) and blood pressure in 7 - 15 years children and adolescents of Beijing so as to provide scientific basis for early prevention of hypertension and to provide evidence for verification on the category criterion of overweight and obesity in children and adolescents of China, recommended by the Working Group on Obesity in China (WGOC) to sensitively distinguish the blood pressure in normal weight, overweight and obesity populations.</p><p><b>METHODS</b>A cross-sectional survey on epidemiological characteristics of obesity with stratified cluster sampling method carried out in Beijing in April and May, 2000. 5155 students aged 6 - 15 years were selecte das research subjects. The category criterion of overweight and obesity in children and adolescents of China was recommended by WGOC, the diagnostic criterion of hypertension in children was recommended by CDC in the USA. Statistics analysis system (SAS 8.1) including partial person correlation analysis, t-test, chi(2) test and logistic multi-factors regression analysis was used to analyses the data from 4982 subjects aged 7 - 15 years.</p><p><b>RESULTS</b>(1) after the age and gender were adjusted, the BMI positive correlation with systolic blood pressure (SBP) and diastolic blood pressure (DBP) was found independent in 7 - 15 years children and adolescents (P < 0.0001) and the partial relation coefficients(r) between BMI and SBP and DBP were 0.323 87 and 0.245 88 respectively. (2) the means of SBP and DBP in obesity group were significantly higher then overweight, while overweight was significantly higher then normal weight group (P < 0.0001). (3) the prevalence rates of hyper-SBP, hyper-DBP and hypertension were significantly different (P < 0.0001). When compared with the normal weight group, the relation risk (RR) for hypertension in overweight group and obesity group were 2.96 and 4.85 respectively. The prevalence rates of hypertension in overweight and obesity group were 19.70% and 24.22% respectively. (4) the results of logistic multi-factors regression analysis showed that both age and weight were effecting on hyper-SBP, hyper-DBP and hypertension (P < 0.0001). After age was adjusted, the RR for hypertension was 2.62, and their confidence interval (CI) was 2.36 - 2.91 in obesity or overweight, between overweight and normal weight.</p><p><b>CONCLUSION</b>(1) the BMI positive correlation with SBP and DBP was found independent in 7 - 15 years children and adolescents of Beijing, and the risk for hypertension maybe increased when these people with overweight and obesity, it is very important for hypertension prevention and control that overweight and obesity prevention and control in children and adolescents. (2) the sensitivity of the category criterion of overweight and obesity in children and adolescents of China, recommended by WGOC have been verified on distinguish the blood pressure in normal weight, overweight and obesity populations.</p>