Precision medicine became the key strategy in development priority of science and technology in China. The large population-based cohorts become valuable resources in preventing and treating major diseases in the population, which can contribute scientific evidence for personalized treatment and precise prevention. The fundamental question of the achievements above, therefore, is how to construct a large population-based cohort in a standardized way. The Chinese Preventive Medicine Association co-ordinated experienced researchers from Peking University and other well-known institutes to write up two group standards Technical specification of data processing for large population-based cohort study (T/CPMA 001-2018) and Technical specification of data security for large population-based cohort study (T/CPMA 002-2018), on data management. The standards are drafted with principles of emphasizing their scientific, normative, feasible, and generalizable nature. In these two standards, the key principles are proposed, and technical specifications are recommended in data standardization, cleansing, quality control, data integration, data privacy protection, and database security and stability management in large cohort studies. The standards aim to guide the large population-based cohorts that have been or intended to be established in China, including national cohorts, regional population cohorts, and special population cohorts, hence, to improve domestic scientific research level and the international influence, and to support decision-making and practice of disease prevention and control.
China ; Cohort Studies ; Delivery of Health Care ; Humans ; Population Surveillance ; Quality Control ; Reference Standards

Objective: To describe the genetic structure of populations in different areas of China, and explore the effects of different strategies to control the confounding factors of the genetic structure in cohort studies. Methods: By using the genome-wide association study (GWAS) on data of 4 500 samples from 10 areas of the China Kadoorie Biobank (CKB), we performed principal components analysis to extract the first and second principal components of the samples for the component two-dimensional diagram generation, and then compared them with the source of sample area to analyze the characteristics of genetic structure of the samples from different areas of China. Based on the CKB cohort data, a simulation data set with cluster sample characteristics such as genetic structure differences and extensive kinship was generated; and the effects of different analysis strategies including traditional analysis scheme and mixed linear model on the inflation factor (λ) were evaluated. Results: There were significant genetic structure differences in different areas of China. Distribution of the principal components of the population genetic structure was basically consistent with the geographical distribution of the project area. The first principal component corresponds to the latitude of different areas, and the second principal component corresponds to the longitude of different areas. The generated simulation data showed high false positive rate (λ=1.16), even if the principal components of the genetic structure was adjusted or the area specific subgroup analysis was performed, λ could not be effectively controlled (λ>1.05); while, by using a mixed linear model adjusting for the kinship matrix, λ was effectively controlled regardless of whether the genetic structure principal component was further adjusted (λ=0.99). Conclusions: There were large differences in genetic structure among populations in different areas of China. In molecular epidemiology studies, bias caused by population genetic structure needs to be carefully treated. For large cohort data with complex genetic structure and extensive kinship, it is necessary to use a mixed linear model for association analysis.
China ; Genetic Structures ; Genome-Wide Association Study ; Humans ; Linear Models ; Principal Component Analysis

Objective: To evaluate the association of educational level with anthropometric measurements at different adult stages and their long-term changes in adults who participated in the second re-survey of China Kadoorie Biobank (CKB). Methods: The present study excluded participants who were aged >65 years, with incomplete or extreme measurement values, or with major chronic diseases at baseline survey or re-survey. The weight at age 25 years was self-reported. Body height, body weight and waist circumference at baseline survey (2004-2008) and re-survey (2013-2014) were analyzed. Results: The present study included 3 427 men and 6 320 women. Both body weight and waist circumference (WC) increased with age. From age 25 years to baseline survey (mean age 45.2±6.5), the mean weight change per 5-year was (1.70±2.63) kg for men and (1.27±2.10) kg for women. From baseline survey to re-survey (53.2±6.5), the mean changes per 5-year for body weight were (1.12±2.61) kg for men and (0.90±2.54) kg for women; and that for WC was (3.20±3.79) cm for men and (3.83±3.85) cm for women. Among women, low educational level was consistently associated with higher body mass index (BMI) and WC at age 25 years, baseline survey and re-survey. Among men, low educational level was associated with higher BMI at age 25 years. At baseline survey and re-survey, the educational level in men was not statistically associated with BMI; but men who completed junior or senior high school showed slight higher WC and increase of WC from baseline survey to re-survey than other male participants. Conclusions: Body weight and WC increased with age for both men and women. The associations of educational level with BMI and WC were different between men and women.
Adult ; Asian People/statistics & numerical data* ; Body Height ; Body Mass Index ; Body Weight ; China/epidemiology* ; Educational Status ; Female ; Humans ; Male ; Middle Aged ; Obesity/ethnology* ; Risk Factors ; Sex Distribution ; Waist Circumference/ethnology*

Objective: To examine the prevalence of 'healthy lifestyle' from data extracted from the China Kadoorie Biobank (CKB) of 0.5 million adults from ten areas across China. Methods: After excluding participants with self-reported histories of coronary heart disease, stroke or cancer, a total of 487 198 participants at baseline (2004-2008) and 22 604 participants at second survey (2013- 2014), were included for analysis. 'Healthy lifestyle' was defined as haing the following characteristics: a) never smoking or having stopped smoking for reasons other than illness; b) alcohol drinking <25 g/day (men)/<15 g/day (women); c) diet rich in vegetables, fruits, legumes and fish, but low in red meat; d) upper quarter of the physical activity level; e) body mass index of 18.5-23.9 kg/m(2) and waist circumstance <85 cm (men)/80 cm (women). We calculated the healthy lifestyle scores (HLS) by counting the number of all the healthy lifestyle factors, with a range from 0 to 6. Results: At baseline, prevalence rates of the above five healthy lifestyles (except physical activity) were 70.6%, 92.6%, 8.7%, 52.6% and 59.0%, respectively, with the mean HLS being 3.1±1.2. Most participants (81.4%) had2-4 healthy components, while only 0.7% (0.2% in men and 1.0% in women) of all the participants had all six healthy lifestyles. Participants who were women, at younger age, with more schooling and rural residents, were more likely to adhere to the healthy lifestyle. After ten years, the mean HLS showed a slight decrease. Conclusion: The prevalence of optimal lifestyles in Chinese adults appeared extremely low. Levels of 'healthy lifestyle' varied greatly among those populations with different socio-demographic characteristics across the ten areas in China.
Adult ; Asian People/statistics & numerical data* ; China ; Female ; Healthy Lifestyle ; Humans ; Life Style ; Male ; Prevalence ; Risk Factors

Objective: To study the relationship between the age of menarche and the near-term/long-term obesity in adult women. Methods: We analyzed the baseline data of 30 895 women with complete data on menarche and body measurement that was from the China Kadoorie Biobank (CKB) study from 2004 to 2008. The age of menarche was divided into three groups: ≤12, 13-16 and ≥17 years old. Prematurity was set at age ≤12 years. Multivariate logistic regression was used to analyze the effects of menarche age on the near/long-term obesity in female adults. Results: The average menarche age of respondent appeared as (15.64±1.92) years old, with prematurity number as 1 421, accounting for 4.6% of the total numbers. Regarding the postponing of dates of birth, the age of menarche in women showed an advancing tendency. Among all the adult women under study, 803 developed near-term obesity, with the prevalence as 2.6%, while the number of long-term obesity was 3 738, accounting for 12.1%. Refining factors of age, lifestyle, menopausal status, hypertension and diabetes showed that the menarche age was related to the risks of both short-term and long-term obesity in women and the ORs (95%CI) were 2.45 (1.74-3.45) and 1.99 (1.69-2.34), respectively. There was no multiplicative interaction shown between the menarche age and menopausal status on long-term obesity (P=0.324). Conclusion: Premature menarche appeared a risk factor for near-term/long-term obesity in adult females.
Adolescent ; Adult ; Age Factors ; China/epidemiology* ; Diabetes Mellitus/epidemiology* ; Female ; Humans ; Menarche ; Obesity/epidemiology* ; Risk Factors

Objective: To evaluate the association of family history with risk of major coronary events (MCE) and ischemic heart disease (IHD). Methods: After excluding participants with heart disease, stroke or cancer at baseline survey, a total of 485 784 participants from the China Kadoorie Biobank, who had no missing data on critical variables, were included in the analysis. Cox regression analysis was used to estimate the hazard ratios (HR) and 95% CI. Subgroup analyses were performed according to the baseline characteristics. Results: During a median of 7.2 years of follow-up, we documented 3 934 incident cases of MCE and 24 537 cases of IHD. In multivariable-adjusted models, family history was significantly associated with risk of MCE and IHD. The adjusted HRs (95%CI) were 1.41 (1.19-1.65) and 1.25 (1.18-1.33), respectively. History of disease among siblings was more strongly associated with early-onset MCE than parental history (HR=2.97, 95%CI: 1.80-4.88). Moreover, the association of family history with MCE and IHD was stronger in persons who were overweight or obesive, and the association between family history and MEC was stronger in smokers. Conclusion: This large-scale, prospective study indicated that family history was an independent risk factor for MCE and IHD in China. The intervention targeting major known lifestyle risk factors and the management of chronic diseases should be strengthened for Chinese population, especially for the individuals with family history were at high risk.
Asian People/statistics & numerical data* ; China/epidemiology* ; Coronary Disease/genetics* ; Humans ; Incidence ; Myocardial Ischemia/genetics* ; Overweight/ethnology* ; Proportional Hazards Models ; Prospective Studies ; Risk Assessment ; Risk Factors ; Smoking/ethnology*

Objective: To assess the implementation and impact of programs carried out by the National Demonstration Areas for Comprehensive Prevention and Control of Non-communicable Diseases. Methods: Both sociological and epidemiological methods were used to collect qualitative and quantitative data in November and December, 2016 in order to conduct on process and outcome evaluation of the above mentioned objective. In the meantime, case study was also conducted. Results: All the National Demonstration Areas for Comprehensive Prevention and Control of Non-communicable Diseases were found well implemented across the country, with health education and health promotion, surveillance and safeguard measures in particular. A government-led and inter-sector coordination and communication mechanism had been well established, with more than 16 non-health departments actively involved. 28.7% of the residents living in the National Demonstration Areas for Comprehensive Prevention and Control of Non-communicable Diseases were aware of the key messages related to chronic diseases. Among the residents, 72.1% of them consumed vegetables and 53.6% consumed fruits daily, with another 86.9% walked at least 10 minutes per day. Over 70% of the patients with hypertension or diabetes reported that they were taken care of by the Community Health Centers, and above 50% of them were under standardized management. Residents, living in the National Demonstration Areas under higher ranking of implementation scores, were more likely to be aware of relevant knowledge on chronic disease control and prevention (OR=6.591, 95%CI: 5.188-8.373), salt reduction (OR=1.352, 95%CI: 1.151-1.589), oil reduction (OR=1.477, 95%CI: 1.249-1.746) and recommendation on physical activities (OR=1.975, 95%CI: 1.623- 2.403). Conclusion: The implementation of programs carried out by the National Demonstration Areas for Comprehensive Prevention and Control of Non-communicable Diseases had served a local platform for the control and prevention of non-communicable diseases, and thus become an important 'carrier' for chronic disease prevention and control programs in China.
China/epidemiology* ; Chronic Disease/epidemiology* ; Delivery of Health Care ; Health Promotion/organization & administration* ; Humans ; National Health Programs ; Noncommunicable Diseases/prevention & control* ; Outcome Assessment, Health Care ; Population Surveillance ; Preventive Health Services/organization & administration* ; Program Evaluation ; Public Health

Objective: To investigate the current status of prevalence, treatment, and management on hypertension among Chinese adults from the National Demonstration Areas for Comprehensive Prevention and Control of Non-communicable Diseases. Methods: We selected a total of 4 000 residents aged ≥18 years for this questionnaire-based survey by multi-stage clustering sampling in 10 National Demonstration Areas between November and December, 2016. Results: There were 3 891 effective questionnaires. The self-reported prevalence of hypertension among aged ≥35 years was 31.47% (1 011/3 213). For the past two weeks, the self-reported treatment of hypertension was 86.75%(877/1 011), with the rates of guidance as 56.87% (575/1 011) on physical activity, 40.95% (414/1 011) on diet, 38.33% (385/1 011) on weight management, and 22.75% (228/1 011) on smoking cessation. For the past 12 months, 74.68% (755/1 011) of the residents aged ≥35 years were under the proper management and 62.12% (628/1 011) of them were under the standardized management programs. The follow-up program lasted for 4 (P(25)-P(75): 4-12) times per year, with 15 (P(25)-P(75): 10-20) minutes per each visit. Hypertensive patients would mainly visit the outpatient clinics (53.51%), followed by home visits (22.91%) and telephone calls (13.64%). Rate of satisfaction on management services was 94.83% (716/755) from the hypertensive patients. Multivariate analysis showed that the rate of self-reported treatment (OR=1.986, 95%CI: 1.222-3.228) and self-reported standardized management (OR=2.204, 95%CI: 1.519-3.199) on hypertension were higher in the Demonstration Areas with higher implementation scores of self-reported non-communicable diseases management. Conclusions: Prevention and management on hypertension in the Demonstration Areas had met the requirement set for the Demonstration Areas during the "12th Five-Year Plan" . Projects on setting up the National Non-communicable Diseases Demonstration Areas had played an active role in promoting the standardized management program on hypertension.
Adult ; Asian People/statistics & numerical data* ; Diet ; Exercise ; Humans ; Hypertension/therapy* ; Noncommunicable Diseases/prevention & control* ; Population Surveillance ; Prevalence ; Risk Factors ; Surveys and Questionnaires

Objective: To describe the regional and population-related differences in calcaneus bone mineral density (BMD) across ten regions of China. Methods: Based on the results: from the second Re-survey of China Kadoorie Biobank project, in which 5% of the surviving participants were interviewed during 2013-2014 and 24 677 participants aged 38-87 years were included in the study. We excluded those people with missing data for BMD and important variables. Calcaneus BMD was measured using the quantitative ultrasound bone densitometer. We analyzed four indexes, including broadband ultrasound attenuation (BUA), speed of sound (SOS), stiffness index (SI), and T score. Results The average calcaneus BMDs of the present population were: BUA (109.7±12.6) dB/MHz, SOS (1 554.7±45.6) m/s, SI (88.3±18.8), T score (-0.74±1.28). Urban residents showed higher calcaneus BMD, so as in men. The calcaneus BMD decreased by age, with a larger decline seen in women. Current smokers and postmenopausal women presented lower calcaneus BMD, while in those who frequently drank milk or yogurt or being physically more active, had higher calcaneus BMD. Conclusion: Calcaneus BMD varied greatly among people from the ten regions of CKB study and among participants having different demographic characteristics, lifestyle behaviors or health conditions.
Absorptiometry, Photon/methods* ; Adult ; Age Factors ; Aged ; Aged, 80 and over ; Bone Density/physiology* ; Calcaneus/diagnostic imaging* ; China ; Female ; Humans ; Male ; Middle Aged ; Residence Characteristics ; Rural Population ; Sex Factors ; Ultrasonography ; Urban Population

Objective: To explore the effect of BMI and waist circumference on diabetes of adults. Methods: After excluding participants with heart disease, stroke, cancer and diabetes at baseline study, 53 916 people aged 30-79 in the China Kadoorie Biobank (CKB) study from Tongxiang city of Zhejiang province were recruited. Cox regression model was used to estimate the hazards ratios (HR) for the associations of baseline BMI and waist circumference with incident diabetes. Results: Among 391 512 person-years of the follow-up program between 2004 and 2013 (median 7.26 years), a total of 944 men and 1 643 women were diagnosed as having diabetes. Compared to those with normal weight, after adjusting for known or potential factors, HR of both overweight and obesity in men for incident diabetes appeared as 2.72 (95%CI: 2.47-2.99) and 6.27 (95%CI: 5.33-7.36), respectively. The corresponding figures in women were 2.19 (95%CI: 2.04-2.36) and 3.78 (95%CI: 3.36-4.26). Compared to those with normal waist circumference, after adjusting for known or potential factors, HR of Ⅰgrade andⅡgrade in men for diabetes were 2.56 (95%CI: 2.22-2.95) and 4.66 (95%CI: 4.14-5.24), respectively. The corresponding figures in women were 1.99 (95%CI: 1.80-2.21) and 3.16 (95%CI: 2.90-3.44), respectively. Conclusions: Overweight, obesity and central obesity were all associated with the increased incident of diabetes. Strategies on diabetes prevention should include not only losing weight, but reducing waist circumference as well.
Adult ; Aged ; Body Mass Index ; China/epidemiology* ; Diabetes Mellitus/ethnology* ; Female ; Humans ; Incidence ; Male ; Middle Aged ; Obesity/epidemiology* ; Obesity, Abdominal/epidemiology* ; Overweight/epidemiology* ; Proportional Hazards Models ; Prospective Studies ; Risk Factors ; Waist Circumference