1.Application of spatial statistics in studying the distribution of food contamination.
X M WANG ; G X XIAO ; J J LIANG ; L X GUO ; Y LIU
Chinese Journal of Epidemiology 2019;40(2):241-246
Objective: Based on data related to arsenic contents in paddy rice, as part of the food safety monitoring programs in 2017, to discuss and explore the application of spatial analysis used for food safety risk assessment. Methods: One province was chosen to study the spatial visualization, spatial point model estimation, and kernel density estimation. Moran's I statistic of spatial autocorrelation methods was used to analyze the spatial distribution at the county level. Results: Data concerning the spatial point model estimation showed that the spatial distribution of pollution appeared relatively dispersive. From the kernel density estimation, we found that the hot spots of pollution were mainly located in the central and eastern regions. The global Moran's I values appeared as 0.11 which presented low spatial aggregation to the rice arsenic contamination and with statistically significant differences. One "high-high" and two typical "low-low" clustering were seen in this study. Conclusion: Results from our study provided good visual demonstration, identification of pollution distribution rules, hot spots and aggregation areas for research on the distribution of food pollutants. Spatial statistics can provide technical support for the implementation of issue-based monitoring programs.
Arsenic/adverse effects*
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China
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Cluster Analysis
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Food Contamination
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Food Supply
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Humans
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Spatial Analysis
2.Prevalence and associated risk factors on preterm birth, low birth weight, and small for gestational age among HIV-infected pregnant women in Hunan province, 2011-2017.
H X LI ; J F ZHENG ; G W HUANG ; J XIAO ; H WANG ; M YANG ; N FENG
Chinese Journal of Epidemiology 2018;39(10):1368-1374
Objective: To describe the prevalence of preterm birth (PB), low birth weight (LBW), and small for gestational age (SGA) among HIV-infected pregnant women and to identify associated risk factors in Hunan province. Methods: This study appeared a retrospective one on HIV-infected pregnant women retrieved from Information System of Prevention of Mother-to-child Transmission of HIV management in Hunan province, between January 2011 and December 2017. Information regarding demographic characteristics, pregnancy, antiretroviral therapy (ART), husbands/partners' relevant situation and pregnancy outcomes, among these HIV-infected pregnant women were collected and analyzed. The incidence rates on PB, LBW and SGA were calculated. Multivariate logistic regression was used to analyze the associated risk factors. Results: A total of 780 HIV-infected pregnant women were enrolled. The prevalence rates on PB, LBW and SGA in HIV- infected pregnant women appeared as 7.9% (62/780), 9.9% (77/780) and 21.3% (166/780), respectively. Results from the multivariate logistic regression analysis showed that factors as pregnancy related diseases as moderate/severe anemia, hypertensive, initial time of ART <14 gestational weeks (compared to those women without ART during pregnancy) and husbands/partners' age >35 years old (compared to husbands/partners' age 26-30 years old) etc., were associated with an increased risk of PB with adjusted OR as 4.59 (95%CI: 1.51-13.95), 4.90 (95%CI: 1.56-15.46), 2.40 (95%CI: 1.26- 4.56) and 2.29 (95%CI: 1.21-4.36). For LBW, pregnancy moderate/severe anemia, pregnancy HBV infection and initial time of ART <14 gestational weeks were associated with an increased risk of LBW, with adjusted OR as 3.28 (95%CI: 1.13-9.54), 4.37 (95%CI: 1.42-13.44) and 2.68 (95%CI: 1.51-4.76), respectively. For SGA, pregnancy HBV infection and initial time of ART <14 gestational weeks were risk factors for SGA, with adjusted OR as 4.41 (95%CI: 1.43-13.63) and 2.67 (95%CI: 1.51-4.73), respectively. Conclusion: Preterm birth, LBW and SGA were common adverse pregnancy outcomes for HIV-infected pregnant women and were associated with factors as pregnancy complications, ART and husbands/partners' age.
Adult
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Birth Weight
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Child
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China/epidemiology*
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Female
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Gestational Age
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HIV Infections/epidemiology*
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Humans
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Infant, Low Birth Weight
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Infant, Newborn
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Infant, Small for Gestational Age
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Pregnancy
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Pregnancy Complications, Infectious/virology*
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Premature Birth/etiology*
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Prevalence
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Retrospective Studies
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Risk Factors
3.Development and validation of a prognostic prediction model for patients with stage Ⅰ to Ⅲ colon cancer incorporating high-risk pathological features.
K X LI ; Q B WU ; F Q ZHAO ; J L ZHANG ; S L LUO ; S D HU ; B WU ; H L LI ; G L LIN ; H Z QIU ; J Y LU ; L XU ; Z WANG ; X H DU ; L KANG ; X WANG ; Z Q WANG ; Q LIU ; Y XIAO
Chinese Journal of Surgery 2023;61(9):753-759
Objective: To examine a predictive model that incorporating high risk pathological factors for the prognosis of stage Ⅰ to Ⅲ colon cancer. Methods: This study retrospectively collected clinicopathological information and survival outcomes of stage Ⅰ~Ⅲ colon cancer patients who underwent curative surgery in 7 tertiary hospitals in China from January 1, 2016 to December 31, 2017. A total of 1 650 patients were enrolled, aged (M(IQR)) 62 (18) years (range: 14 to 100). There were 963 males and 687 females. The median follow-up period was 51 months. The Cox proportional hazardous regression model was utilized to select high-risk pathological factors, establish the nomogram and scoring system. The Bootstrap resampling method was utilized for internal validation of the model, the concordance index (C-index) was used to assess discrimination and calibration curves were presented to assess model calibration. The Kaplan-Meier method was used to plot survival curves after risk grouping, and Cox regression was used to compare disease-free survival between subgroups. Results: Age (HR=1.020, 95%CI: 1.008 to 1.033, P=0.001), T stage (T3:HR=1.995,95%CI:1.062 to 3.750,P=0.032;T4:HR=4.196, 95%CI: 2.188 to 8.045, P<0.01), N stage (N1: HR=1.834, 95%CI: 1.307 to 2.574, P<0.01; N2: HR=3.970, 95%CI: 2.724 to 5.787, P<0.01) and number of lymph nodes examined (≥36: HR=0.438, 95%CI: 0.242 to 0.790, P=0.006) were independently associated with disease-free survival. The C-index of the scoring model (model 1) based on age, T stage, N stage, and dichotomous variables of the lymph nodes examined (<12 and ≥12) was 0.723, and the C-index of the scoring model (model 2) based on age, T stage, N stage, and multi-categorical variables of the lymph nodes examined (<12, 12 to <24, 24 to <36, and ≥36) was 0.726. A scoring system was established based on age, T stage, N stage, and multi-categorical variables of lymph nodes examined, the 3-year DFS of the low-risk (≤1), middle-risk (2 to 4) and high-risk (≥5) group were 96.3% (n=711), 89.0% (n=626) and 71.4% (n=313), respectively. Statistically significant difference was observed among groups (P<0.01). Conclusions: The number of lymph nodes examined was an independent prognostic factor for disease-free survival after curative surgery in patients with stage Ⅰ to Ⅲ colon cancer. Incorporating the number of lymph nodes examined as a multi-categorical variable into the T and N staging system could improve prognostic predictive validity.
Male
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Female
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Humans
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Prognosis
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Neoplasm Staging
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Retrospective Studies
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Nomograms
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Lymph Nodes/pathology*
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Risk Factors
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Colonic Neoplasms/surgery*