Objective: To explore the sampling method in China National Human Biomonitoring Program (HBP) and the related errors, so as to calculate and evaluate the study design in sampling. Methods: The sampling method of HBP is of multistage nature. Taking the results of sampling method from Guizhou province as an example, results related to sampling error and variation coefficient were calculated, using the multistage unequal probability sampling error method. Results: The HBP covered 152 monitoring sites in 31 provinces (autonomous regions and municipalities) and with 21 888 residents selected. The replacement rates at various stages were 5.26%, 6.35% and 40.6% respectively. The sampling error in Guizhou province was 3 207 594, and the coefficient of variation was 0.097. Conclusions: According to the multi-stage unequal probability sampling method, the sampling coefficient variability appeared small with high precision, in Guizhou province. However, this method did not consider the weight adjustment of non-sampling errors such as population missing rate and response rate. Methods related to the calculation on multi-stage sampling error among large-scale public health monitoring projects need to be further studied.
China ; Cities ; Environmental Monitoring ; Humans ; Research Design

Objective: To estimate the association between high-sensitivity C-reactive protein (hs-CRP) and cardiovascular events as well as all-cause mortality events. Methods: During 2009- 2010, out of the 11 623 individuals, 1 000 participants aged 35-64 years, were recruited and divided into 12 age-groups, to have received a study on CVD risk factors. Information on the risk factors of cardiovascular diseases was also collected. Fasting blood sample was gathered for all the participants, with hs-CRP tested. Participants in 7 out of the 12 sites were followed, with 6.21 years (36 075 person-years) as the median follow-up period. Cardiovascular and all-cause mortality events were collected. A total of 6 177 participants had been followed after excluding participants who had baseline infections, or did not take hs-CRP test/physical examination at the baseline. Finally, 5 984 participants were included for analysis. Participants were categorized into three groups based on the hs-CRP (mg/L) values: <1, 1-3 and >3, respectively. Cox proportional hazards regression model was used to analyze the relationships between hs-CRP with cardiovascular events or all-cause mortality events, after adjusting for confounding factors. Results: Mean age of the participants was 50.2 years. The incidence rates of cardiovascular disease events were 3.6/1 000 person-years, 7.1/1 000 person-years,and 10.4/1 000 person-years among three groups and 3.0/1 000 person-years, 5.7/1 000 person-years, 9.1/1 000 person-years for all-cause mortality events, respectively. After adjusting for confounding factors, the hazard risks (HR) for cardiovascular events were 1.33 (95%CI: 0.95-1.84) in the hs-CRP 1-3 mg/L group and 1.76 (95%CI: 1.20-2.60) in the hs-CRP>3 mg/L group when comparing with the hs-CRP<1 mg/L group (trend test P=0.003). The HRs for all-cause mortality events were 1.76 (95%CI: 1.23-2.54) and 2.64 (95%CI: 1.74-4.01) (trend test P<0.001), respectively. Conclusion: Hs-CRP appeared an independent predictor for cardiovascular events and all-cause mortality events.
Adult ; Asian People ; C-Reactive Protein/metabolism* ; Cardiovascular Diseases/mortality* ; China/epidemiology* ; Female ; Hospital Mortality ; Humans ; Incidence ; Male ; Middle Aged ; Proportional Hazards Models ; Risk Factors

Objective: To explore the relationship of family environment in childhood and adolescence and mental health in adulthood. Methods: A total of 791 subjects aged ≥25 years were selected through the Chinese National Twin Registry (CNTR). The short-form of Family Environment Scale-Chinese Version (FES-CV) was used to evaluate the family environment during childhood and adolescence in three dimensions: relationship, system maintenance and personal growth. The mental health status in adulthood was assessed with the Chinese version of 6-item Kessler Psychological Distress Scale (K6). The generalized linear mixed model was used to examine their relationship. Results: About 4.6% of the subjects reported general or worse mental health status. Compared with the subjects with good mental status, statistical difference was observed only in parenting way among twins (living together or not). After adjusting the potential confounders, such as age, sex, zygosity, education and lifestyle (smoking, drinking and physical activity), good family relationship and system maintenance had a positive effect on mental health, with the OR (95%CI) of 0.66 (0.51-0.87) and 0.70 (0.50-0.98) respectively. Furthermore, parenting way did not modify the effect of family environment on mental health status in adulthood (interaction: P>0.05). In each scale, scores of cohesion and organization were positively correlated with mental health, while the score of conflict was negatively correlated with the mental health. Conclusion: Good family relationship and system maintenance in childhood and adolescence had a positive impact on mental health in adulthood.
Adolescent ; Adult ; Child ; China ; Family Relations ; Female ; Humans ; Interpersonal Relations ; Male ; Mental Health ; Parenting

The prevalence of child and adolescent growth and mental-behavior related diseases are increasing, and the pathogenesis are complex. Twins are excellent natural resources for complex chronic diseases research as they share the maternal intrauterine environment, born at the same time and share the same family environment in early years, which could benefit the adjust ment of confounding factors, such as age, genetic factors and early family environmental factors. Birth cohort with twin families involved could be more effective in exploring the genetic and environmental factors for complex chronic diseases at the very beginning of life. This paper summarizes the objective, content, progress, strengths and potential problems of Wuhan Twin Birth Cohort, with emphasis on the overall design and progress of the study.
Adolescent ; Asian People ; Birth Weight ; Child ; China ; Cohort Studies ; Diseases in Twins/genetics* ; Epidemiological Monitoring ; Female ; Humans ; Male ; Twin Studies as Topic ; Twins