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

Heavy metal is one of pollutants existed widely in the environment, its relationship with cardiovascular disease has attracted more and more attention. In this review, the concentrations of heavy metals, including lead, cadium and asenic, in the body from several national surveillance networks and the epidemiological studies on the effects of the exposure of three heavy metals on cardiovascular system were summarized. It is suggested to strengthen nationwide surveillance for body concentrations of heavy metals in general population in order to provide baseline data for quantitative evaluation of the risk of heavy metal exposure on cardiovascular disease.
Cadmium ; Cardiovascular Diseases/chemically induced* ; Environmental Exposure/adverse effects* ; Environmental Pollutants/toxicity* ; Epidemiologic Studies ; Humans ; Lead/toxicity* ; Metals, Heavy/toxicity* ; Neoplasms ; Research/trends*

Objective: To understand the related risk behaviors, knowledge and status of HIV/AIDS infection among rural adults of Derung minority, to provide relevant messages for the development of HIV/AIDS intervention strategy in this minority group. Methods: We used system sampling method to conduct a cross-sectional survey in 6 administration villages of Derung Township, Gongshan Derung and Nu Autonomous County in Nujiang Lisu Autonomous Prefecture of Yunnan Province, with a sample size estimated as 383. Adult residents with Derung minority in six villages of Gongshan County were involved, with relevant information collected through door-to-door visit. HIV antibody was tested and SPSS 17.0 was used for statistical analysis. Results: Information on 394 valid respondents was collected, with age as between 18 and 65 (34.39±9.74), 80.7% (318/394) as married, 54.0% (213/394) having had primary school education, 13.2% (52/394) as migrant workers. In this population, the overall HIV infection rate appeared as 0.5% (2/400), mainly through sexually transmission. The rate of awareness on HIV/AIDS was 69.8% (275/394), mainly through free publicized materials 50.0% (197/394). Rates on premarital sexual behavior on multiple sexual partners in the past year, on temporary sexual partners in the past year, having commercial sexual experiences in the past year and ever used condoms when engaging in casual sex, were 6.4% (60/366), 18.0%(66/366), 5.7%(21/366), 1.9%(7/366) and 8.0%(25/311), respectively. Conclusions: Few numbers of HIV infections were identified among the migrating workers with Derung minority, with sexual transmission as the major route, along with the increased number of rural migrant workers and the low rates both on AIDS knowledge and condom use, accompanied by the high risk sexual behavior appeared in this rural adult residents of Derung minority. Relative strategies on HIV/AIDS intervention and control should be developed.
Acquired Immunodeficiency Syndrome ; Adult ; China/epidemiology* ; Condoms ; Cross-Sectional Studies ; HIV Infections/epidemiology* ; Health Knowledge, Attitudes, Practice ; Humans ; Infections ; Risk-Taking ; Rural Population/statistics & numerical data* ; Sexual Behavior ; Sexual Partners ; Surveys and Questionnaires ; Transients and Migrants

Objective: To investigate the association between maternal pre-pregnant body mass index and gestational weight gain, as well as their interaction on neonatal birthweight. Methods: We built a cohort in Anqing Municipal Hospital from January 2014 to March 2015, enrolling pregnant women who decided to give birth in this hospital. All women were asked to fill a questionnaire for basic information collection. Medical information of both pregnant women and their newborns were obtained through electronic medical record. Chi-square analysis, multinomial logistic regression, multiplicative and additive interaction methods were used to analyze the association between pre-pregnant body mass index and gestational weight gain as well as their interactions on birth weight of the neonates. Results: A total of 2 881 pregnant women were included in this study. Of the 2 881 newborns, 359 (12.46%) were small for gestational age (SGA) and 273 (9.48%) were large for gestational age (LGA). After adjusting the possible confounding factors, results from the multinomial logistic regression showed that pre-pregnancy underweight women were more possible to deliver SGA (aRR=1.33, 95%CI: 1.02-1.73). If the gestational weight gain was below the recommended criteria, the risk of SGA (aRR=1.64, 95%CI: 1.23-2.19) might increase. Pre-pregnancy overweight/obese could increase the risk of being LGA (aRR=1.86, 95%CI: 1.33-2.60). Maternal gestational weight gain above the recommendation level was associated with higher rates of LGA (aRR=2.03, 95%CI: 1.49-2.78). Results from the interaction analysis showed that there appeared no significant interaction between pre-pregnancy BMI and gestational weight on birthweight. Conclusion: Pre-pregnancy body mass index and gestational weight gain were independently associated with neonatal birthweight while pre-pregnancy BMI and gestational weight gain did not present interaction on birthweight.
Birth Weight ; Body Mass Index ; Body Weight ; China/epidemiology* ; Cohort Studies ; Female ; Gestational Weight Gain ; Humans ; Infant, Newborn ; Infant, Small for Gestational Age ; Logistic Models ; Obesity/epidemiology* ; Overweight/epidemiology* ; Pregnancy ; Pregnancy Complications ; Pregnant Women ; Risk Factors ; Thinness/epidemiology* ; Weight Gain

Objective: To investigate the clinicopathological characteristics, immunohistochemical profiles, molecular features, and prognosis of subungual melanoma in situ (SMIS). Methods: Thirty cases of SMIS were collected in Fudan University Shanghai Cancer Center, Shanghai, China from 2018 to 2022. The clinicopathological characteristics and follow-up data were retrospectively analyzed. Histopathologic evaluation and immunohistochemical studies were carried out. By using Vysis melanoma fluorescence in situ hybridization (FISH) probe kit, combined with 9p21(CDKN2A) and 8q24(MYC) assays were performed. Results: There were 8 males and 22 females. The patients' ages ranged from 22 to 65 years (median 48 years). All patients presented with longitudinal melanonychia involving a single digit. Thumb was the most commonly affected digit (16/30, 53.3%). 56.7% (17/30) of the cases presented with Hutchinson's sign. Microscopically, melanocytes proliferated along the dermo-epithelial junction. Hyperchromatism and nuclear pleomorphism were two of the most common histological features. The melanocyte count ranged from 30 to 185. Most cases showed small to medium nuclear enlargement (29/30, 96.7%). Pagetoid spread was seen in all cases. Intra-epithelial mitoses were identified in 56.7% (17/30) of the cases. Involvement of nailfold was found in 19 cases, 4 of which were accompanied by cutaneous adnexal extension. The positive rates of SOX10, PNL2, Melan A, HMB45, S-100, and PRAME were 100.0%, 100.0%, 96.0%, 95.0%, 76.9%, and 83.3%, respectively. FISH analysis was positive in 6/9 of the cases. Follow-up data were available in 28 patients, and all of them were alive without disease. Conclusions: SMIS mainly shows small to medium-sized cells. High melanocyte count, hyperchromatism, nuclear pleomorphism, Pagetoid spreading, intra-epithelial mitosis, nailfold involvement, and cutaneous adnexal extension are important diagnostic hallmarks. Immunohistochemistry including SOX10 and PRAME, combined with FISH analysis, is valuable for the diagnosis of SMIS.
Male ; Female ; Humans ; Young Adult ; Adult ; Middle Aged ; Aged ; Skin Neoplasms/pathology* ; Prognosis ; Retrospective Studies ; In Situ Hybridization, Fluorescence ; China ; Melanoma/diagnosis* ; Nail Diseases/pathology* ; Antigens, Neoplasm

Objective: To understand the seasonal distribution of patient hospitalization due to asthma exacerbation in 7 geographic areas in China. Methods: This was a retrospective study which involved patients hospitalized for asthma exacerbation in 29 hospitals throughout 7 geographic areas in the mainland of China (northeast, north, central, east, south, northwest and southwest). The numbers of asthmatic patients and total inpatients of the respiratory department of each hospital were recorded. The monthly ratio of asthmatic patients to the total inpatients in every area was calculated and compared. Results: During the study period, 6 480 patients were admitted for asthma exacerbation, accounting for 3.14% of all the 206 135 patients admitted to the respiratory departments in the 29 hospitals. The ratio of asthmatic patients to total inpatients in the northeast area (5.61%) was highest, and the ratio in east area was lowest (1.97%). Statistical analysis showed that the difference among different areas was significant (P<0.000 1). In most areas, both the number and proportion of hospitalized asthmatic patients peaked in spring (February-April) and autumn (September-October). In the northeast area, east area and south area, the peaks in spring were more obvious, while in the north area and southwest area, the peaks in autumn were more obvious. In the northwest area the peaks occurred in winter (December-January) and summer (June-August), respectively. The differences in hospitalization due to asthma among different months were significant in the northeast, north, and southwest areas (P<0.005). Conclusion: The number of patients hospitalized for asthma exacerbation fluctuated with season in different areas in China. In most areas, more asthmatic patients were admitted to hospitals in spring and autumn.
Asthma ; China/epidemiology* ; Hospitalization/statistics & numerical data* ; Humans ; Retrospective Studies ; Seasons

One of the commonly accepted merits of cohort studies (CSs) refers to the exposure precedes outcome superior to other observational designs. We use Directed Acyclic Graphs to construct a causal graph among research populations under CSs. We notice that the substitution of research population in place of a susceptible one can be used for effect estimation. Its correctness depends on the outcome-free status of the substituted population and the performance of both screening and diagnosis regarding the outcomes under study at baseline. The temporal precedence of exposure over outcome occurs theoretically, despite the opposite happens in realities. Correct effect estimate is affected by both the suitability of population substitution and the validities of outcome identification and exclusion.
Causality ; Cohort Studies ; Confounding Factors, Epidemiologic ; Epidemiologic Methods ; Mass Screening ; Research Design

Confounding affects the causal relation among the population. Depending on whether the confounders are known, measurable or measured, they can be divided into four categories. Based on Directed Acyclic Graphs, the strategies for confounding control can be classified as (1) the broken-confounding-path method, which can be further divided into single and dual broken paths, corresponding to exposure complete intervention, restriction and stratification, (2) and the reserved-confounding-path method, which can be further divided into incomplete exposure intervention (in instrumental variable design and non-perfect random control test), mediator method and matching method. Among them, random control test, instrumental variable design or Mendelian randomized design, mediator method can meet the requirements for controlling all four types of confounders, while the restriction, stratification and matching methods are only applicable to known, measurable and measured confounders. Identifying the mechanisms of confounding control is a prerequisite for obtaining correct causal effect estimates, which will be helpful in research design.
Causality ; Confounding Factors, Epidemiologic ; Humans ; Models, Statistical ; Random Allocation ; Randomized Controlled Trials as Topic ; Research Design

Objective: To explore the survival factors and construct a prognostic index (PI) for oral squamous cell carcinoma (OSCC). Methods: From January 2004 to June 2016, a total of 634 patients with pathologically confirmed OSCC were recruited in a hospital of Fujian. The clinical and follow-up data of all the patients with pathologically confirmed OSCC were collected to identify the factors influencing the prognosis of OSCC. All the patients were randomly divided into two groups: modeling group (modeling dataset, n=318) and validation group (validation dataset, n=316). Randomization was carried out by using computer-generated random numbers. In the modeling dataset, survival rates were calculated using Kaplan-Meier method and compared using the log-rank test. Cox regression model was used to estimate the hazard ratio (HRs) and 95% confidence intervals (CIs) of prognosis factors. An PI for OSCC patients prognostic prediction model was developed based on β value of each significant variable obtained from the multivariate Cox regression model. Using the tertile analysis, patients were divided into high-risk group, moderate-risk group, and low-risk group according to the PI, the Akaike information criterion (AIC) and Harrell's c-statistic (C index) were used to evaluated the model's predictability. Results: Results from the multivariate Cox regression model indicated that aged ≥55 years (HR=2.22, 95%CI: 1.45-3.39), poor oral hygiene (HR=2.12, 95%CI: 1.27-3.54), first diagnosis of lymph node metastasis (HR=5.78, 95%CI: 3.60-9.27), TNM stage Ⅲ-Ⅳ (stage Ⅰ as reference) (HR=2.43, 95%CI: 1.10-5.37) and poor differentiation (well differentiation as reference) (HR=2.53, 95%CI: 1.60-4.01) were the risk factors influencing the prognosis of OSCC. The PI model had a high predictability in modeling group and validation group (AIC and C index were 1 205.80, 0.700 2 and 1 150.47, 0.737 3). Conclusion: Age, poor oral hygiene, first diagnosis of lymph node metastasis, TNM stage and histological grade were factors associated with the prognosis of OSCC, and the PI model has a certain significance in the clinical treatment of OSCC.
Carcinoma, Squamous Cell/therapy* ; China/epidemiology* ; Humans ; Lymphatic Metastasis ; Middle Aged ; Mouth Neoplasms/therapy* ; Prognosis ; Proportional Hazards Models ; Risk Factors ; Survival Rate ; Treatment Outcome

Objective: To know the situation of extramarital sexual behaviors and HIV infection in middle-aged and elderly people in Chongqing, and provide reference for AIDS prevention and treatment. Methods: From October to December 2017, a multi-stage sampling method was used to recruit middleaged and elderly people aged ≥50 years who lived in Dazu and Hechuan districts of Chongqing for at least one year, with a sample size of 410. Face-to-face questionnaires survey and HIV antibody test were conducted. Results: A total of 408 people were surveyed, including 313 males and 95 females aged 50-88 (64.93±9.03) years. The HIV infection rate was 1.47% (6/408), with the rate of 1.28% (4/313) in males and 2.11% (2/95) in females. The awareness rate of AIDS related knowledge was 37.50% (153/408). And 18.87% (77/408) of subjects surveyed reported extramarital sexual behaviors, 7.60% (31/408) reported extramarital sexual behaviors in the past half year, the constant condom use rate was 19.35% (6/31). The results of multivariate logistics model analysis on extramarital sexual behaviors showed that the prevalence in males were 39.51 times higher than that in females (OR=39.51, 95%CI: 5.03-310.30), 4.60 times higher in those who were unmarried, divorced or widowed than that in the married or cohabitants (OR=4.60, 95%CI: 1.50-14.05), 2.03 times higher in those with outside activities than those with individual activities (OR=2.03, 95%CI: 1.08-3.81) and 3.94 times higher in those with self-evaluation of emptiness of living state than that in those with engaged life (OR=3.94, 95%CI: 1.86-8.36). Conclusions: The prevalence of extramarital sexual behavior in middle-aged and elderly people in some counties and districts in Chongqing is high. The factors such as gender, marital status, leisure activities, and self-evaluation of living state were related to the prevalence of extramarital sexual behaviors in this population. The condom use rate in extramarital sexual behavior was low. It is necessary to take effective interventions in this population.
Aged ; Aged, 80 and over ; China/epidemiology* ; Condoms ; Extramarital Relations ; Female ; HIV Infections/transmission* ; Humans ; Male ; Marital Status ; Middle Aged ; Risk Factors ; Sexual Behavior ; Surveys and Questionnaires