1.Statistical approaches to causal inference in environmental epidemiology: Methodological introductions and R implementations
Guiming ZHU ; Wanying LIU ; Yanchao WEN ; Simin HE ; Qian GAO ; Tong WANG
Journal of Environmental and Occupational Medicine 2026;43(2):253-260
Environmental pollution is a significant public health challenge worldwide, and investigating the causal relationship between environmental exposure and population health outcomes is a key objective of environmental epidemiology research. In recent years, the complexity of environmental exposures has increasingly come to the forefront, making it challenging for observational studies that dominate environmental epidemiology to accurately estimate causal effects. Causal inference methods are particularly advantageous in controlling for confounding factors, thus holding great potential in environmental epidemiology research. Researchers can use appropriate causal inference methods to simulate the process of randomization, providing strong support for revealing the causal relationship between environmental exposure and health outcomes. However, there is a lack of reviews on the application of causal inference methods in environmental epidemiology studies in China. Therefore, this study introduced the basic principles of common causal inference statistical methods in environmental epidemiology, summarized the applicable conditions, advantages and disadvantages of various methods, and provided R software implementation codes for these methods, aiming to offer guidance for optimizing research design and practicing causal inference statistical methods.
2.Preliminary evaluation of the effect of comprehensive health management on the prevention and treatment of ischemic stroke
Shuai ZHU ; Genming ZHAO ; Yiying ZHANG ; Dongni LIANG ; Hongjie YU ; Qian PENG ; Fang XIANG ; Na WANG
Journal of Public Health and Preventive Medicine 2026;37(2):89-93
Objective To evaluate the short-term effects of comprehensive health management interventions for stroke high-risk population screening on the prevention and treatment of ischemic stroke, and to provide reference and basis for improving and exploring health management and prevention strategies for stroke high-risk population. Methods From 2018 to 2022, 13 community health service centers in Jiading District, Shanghai were selected in the present study. Based on information push platform, stroke risk assessment and health intervention follow-up were conducted for community residents through convenience sampling. The residents were divided into a full course intervention group (intervention group) and a routine intervention group (control group) according to different health intervention measures and forms. The incidence of ischemic stroke in the two groups of survey subjects was tracked within 36 months. Results A total of 52144 subjects were included in the study. The total number of patients in the full course intervention group was 14227, with an incidence density of 577.32/100 000 (556.49/100 000-598.12/100 000), which was lower than that of the conventional intervention group (37 917), with an incidence density of 1 485.47/100 000 (1 464.99/100 000-1 505.94/100 000) (χ2=2490.212, P<0.001). The relative risk of the full course intervention group was 0.39, and the relative risk of stroke risk factors in the full course intervention group from low to high was 0.33, 0.43, 0.45, and 0.49, respectively. The incidence density of males in the full course intervention group was 660.76 (627.46/100 000 - 694.05/100 000), with a relative risk of 0.43, and the incidence density of female patients was 509.71/100 000 (483.37/100 000 - 536.05/100 000), with a relative risk of 0.35. The overall incidence density of the population under 62 years old gourp, 62-75 years old group and over 75 years old group was 197.45/100 000 (173.09/100 000 -221.80/100 000), 608.36/100 000 (580.19/100 000-636.54/100 000), and 1 025.06/100 000 (958.51/100 000-1 091.61/100 000), with relative risks of 0.51, 0.44, and 0.38, respectively. Conclusion Comprehensive health management measures can effectively reduce the short-term risk of ischemic stroke, and should be further promoted and improved to enhance the effectiveness of stroke prevention and control.
3.Association between occupational lead exposure and multiple health indicators: A machine learning-based study
Jiali QIAN ; Boshen WANG ; Qinheng ZHU ; Xiaoru DAI ; Baoli ZHU
Journal of Environmental and Occupational Medicine 2026;43(5):621-629
Background Lead (Pb) is a highly toxic heavy metal that accumulates in the body, potentially leading to multi-systemic impairment. Compared with traditional statistical methods, machine learning techniques offer unique advantages, opening new avenues for occupational health risk assessment and the exploratory analysis of complex associations. Objective To examine the association between occupational lead exposure and multiple health indicators and to identify key risk factors for lead toxicity. Methods A cross-sectional study was conducted, integrating occupational hygiene investigation results from 16 lead-acid battery enterprises in Jiangsu Province with occupational health examination data from 1914 lead-exposed workers. Inter-group differences were analyzed using the χ2 test or Fisher's exact test. Binary logistic regression and machine learning algorithms [CatBoost, Naive Bayes model (NBM), and random forest (RF)] were employed to evaluate the association between blood lead (PbB), urine lead (PbU), and health indicators including blood pressure (BP), red blood cell count (RBC), and alanine aminotransferase (ALT). Results The prevalence of abnormal PbB and PbU were 14.52% and 9.35%, respectively. The risks of abnormal BP, RBC, and ALT were significantly increased in the population with high lead levels (P<0.05). PbB abnormalities were closely associated with gender, environmental lead concentration, wearing masks, smoking, and alcohol consumption (P<0.05). Regarding occupational hazards, workers exposed to lead dust had a 1.98-fold risk of PbU abnormality compared to those exposed to lead fumes. The plate coating and acid leaching process posed the highest risk for both PbB (OR=8.81) and PbU (OR=5.46) abnormalities compared with assembly process. Furthermore, the risks of PbB and PbU abnormalities were significantly elevated among workers with abnormal BP, RBC or ALT (P<0.05). Among the models, CatBoost performed best in predicting RBC abnormality (accuracy: 95.8%; precision: 44.9%; F1 score: 0.952; AUC: 0.981). Feature importance analysis identified PbB and PbU as the core factors affecting abnormal RBC and ALT, while RBC and ALT abnormalities as key features for predicting the risk of PbB and PbU abnormalities. Conclusion By integrating traditional statistical methods with machine learning, this study reveals a complex bidirectional association between occupational lead exposure and multiple health indicators, and identifies gender, job category, and environmental Pb concentration as the key factors influencing PbB abnormalities. These findings provide a scientific foundation for the implementation of precision occupational health management models.
4.Hourly ozone concentration estimation and its health impact study based on ensemble machine learning: A case study of Taiyuan City
Rule DU ; Xiaojuan YANG ; Ruixia NIU ; Yang XU ; Guiming ZHU ; Qian GAO ; Tong WANG
Journal of Environmental and Occupational Medicine 2026;43(1):8-15
Background Ozone (O3) is a major air pollutant. The existing monitoring system has uneven distribution of sites, insufficient coverage in underdeveloped areas, and low temporal resolution, making it difficult to obtain hourly data. This limits the dynamic identification of pollution and the formulation of prevention and control strategies. Objective To construct an hourly O3 concentration estimation model based on ensemble machine learning, aiming to improve the accuracy of pollution exposure assessment and explore O3 health impacts. Methods This study integrated land use regression modeling with modern machine learning techniques, employing random forest and XGBoost algorithms to construct base models, and stacking integration using non-negative least squares. The ensemble model was trained and validated across China using high-resolution, multi-source geographic data (e.g., meteorologicaldata, population density, land cover types, and aerosol optical thickness). It was tested in Taiyuan City, combined with a distributed lag non-linear model to analyze the association between O3 and emergency admissions. Results The constructed ensemble model performed well in predicting O3 concentration, with a higher coefficient of determination (R2) and a lower root-mean-square deviation (RMSE) compared to the single models. The R2 improved from 0.90 to 0.92, and the RMSE decreased from 11.41 to 10.62, enhancing both prediction accuracy and generalization ability. In the application to Taiyuan City, the model successfully imputed the hourly-level data for the entire year. The distributed lag non-linear model analysis revealed that the relative risk (RR) values for the 6th to 8th days following O3 exposure were 1.14 (95%CI: 1.01, 1.29), 1.16 (95%CI: 1.02, 1.31), and 1.14 (95%CI: 1.01, 1.29), respectively, which were significantly higher than 1, indicating a significant lagged association (lagged 6-8 d) between O3 and the number of emergency room visits. Conclusion A high-precision, hourly-level O3 concentration estimation model is successfully constructed by combining the land use regression model with an ensemble machine learning approach to provide a scientific basis for environmental policy formulation and public health intervention. The application of the model verifies its generalization ability and practical application value, which can provide a new technical framework for subsequent environmental health research.
5.Association between occupational lead exposure and multiple health indicators: A machine learning-based study
Jiali QIAN ; Boshen WANG ; Qinheng ZHU ; Xiaoru DAI ; Baoli ZHU
Journal of Environmental and Occupational Medicine 2026;43(5):621-629
Background Lead (Pb) is a highly toxic heavy metal that accumulates in the body, potentially leading to multi-systemic impairment. Compared with traditional statistical methods, machine learning techniques offer unique advantages, opening new avenues for occupational health risk assessment and the exploratory analysis of complex associations. Objective To examine the association between occupational lead exposure and multiple health indicators and to identify key risk factors for lead toxicity. Methods A cross-sectional study was conducted, integrating occupational hygiene investigation results from 16 lead-acid battery enterprises in Jiangsu Province with occupational health examination data from 1914 lead-exposed workers. Inter-group differences were analyzed using the χ2 test or Fisher's exact test. Binary logistic regression and machine learning algorithms [CatBoost, Naive Bayes model (NBM), and random forest (RF)] were employed to evaluate the association between blood lead (PbB), urine lead (PbU), and health indicators including blood pressure (BP), red blood cell count (RBC), and alanine aminotransferase (ALT). Results The prevalence of abnormal PbB and PbU were 14.52% and 9.35%, respectively. The risks of abnormal BP, RBC, and ALT were significantly increased in the population with high lead levels (P<0.05). PbB abnormalities were closely associated with gender, environmental lead concentration, wearing masks, smoking, and alcohol consumption (P<0.05). Regarding occupational hazards, workers exposed to lead dust had a 1.98-fold risk of PbU abnormality compared to those exposed to lead fumes. The plate coating and acid leaching process posed the highest risk for both PbB (OR=8.81) and PbU (OR=5.46) abnormalities compared with assembly process. Furthermore, the risks of PbB and PbU abnormalities were significantly elevated among workers with abnormal BP, RBC or ALT (P<0.05). Among the models, CatBoost performed best in predicting RBC abnormality (accuracy: 95.8%; precision: 44.9%; F1 score: 0.952; AUC: 0.981). Feature importance analysis identified PbB and PbU as the core factors affecting abnormal RBC and ALT, while RBC and ALT abnormalities as key features for predicting the risk of PbB and PbU abnormalities. Conclusion By integrating traditional statistical methods with machine learning, this study reveals a complex bidirectional association between occupational lead exposure and multiple health indicators, and identifies gender, job category, and environmental Pb concentration as the key factors influencing PbB abnormalities. These findings provide a scientific foundation for the implementation of precision occupational health management models.
6.Application of visualized thermosensitive color-changing bolus in postmastectomy radiotherapy for breast cancer
Yong WANG ; Yanze SUN ; Wenmin HAN ; Jianjun QIAN ; Peifeng ZHAO ; Liesong CHEN ; Yaqun ZHU ; Ye TIAN
Chinese Journal of Radiological Medicine and Protection 2025;45(5):431-437
Objective:To explore the feasibility and advantages of applying visualized thermosensitive color-changing bolus in postmastectomy radiotherapy (PMRT) for breast cancer.Methods:Forty patients with breast cancer treated with PMRT in the Second Affiliated Hospital of Soochow University from June 2023 to June 2024 were prospectively selected. They were randomly divided into test and control groups (also referred to as groups A and B, respectively), with 20 patients in each group. Group A, underwent two CT scans: the first scan without bolus (image A1) and the second scan with visualized thermosensitive color-changing bolus (image A2). They were treated with visualized thermosensitive color-changing bolus. Group B also underwent two CT scans: the first scan without bolus (image B1) and the second scan with conventional commercial bolus (image B2), and then were treated with conventional commercial bolus. In the radiotherapy planning, images A1 and A2 were designed as A1-Plan and A2-Plan, and A3-Plan was created by transferring the A1-Plan onto image A2. Images B1 and B2 were designed as B1-Plan and B2-Plan, and B3-Plan was created by transferring the B1-Plan onto image B2. The radiation fields and target optimization functions were identical. The dosimetric differences and skin toxicity reactions between different plans were compared.Results:In Group A, A1-Plan and A2-Plan manifested no statistically significant differences ( P > 0.05) in the doses to organs at risk (OARs), including the ipsilateral lung ( V5 Gy, V10 Gy, V20 Gy), heart ( Dmean), contralateral breast ( Dmean), and skin ( Dmax and Dmean), target homogeneity index (HI), conformity index (CI), prescription dose volume ( V50 Gy), depth of maximum dose ( Dmax), and monitor unit (MU). In Group B, B3-Plan compared to B1-Plan showed reduced V50 Gy (89.9% vs. 95%), HI (0.153 vs. 0.136), and CI (0.817 vs. 0.810), while the two plans displayed no statistically significant differences in doses to OARs. In contrast, A3-Plan and B3-Plan exhibited statistically significant differences ( t = 2.78, 2.29, -0.47, 0.51, 3.13, P < 0.05) in V50 Gy (94.05% vs. 89.90%), Dmax (5 665.4 cGy vs. 5 632.7 cGy), HI (0.148 vs. 0.163), CI (0.83 vs. 0.82), and skin Dmean (5 153.6 cGy vs. 5 048.2 cGy). Compared to the conventional commercial bolus of the same thickness, the visualized thermosensitive color-changing bolus yielded a significantly reduced air cavity volume (3 833 mm 3vs. 21 498 mm 3,t = -9.65, P < 0.05). Both groups experienced only grade I skin toxicity reactions. Conclusions:Compared to the conventional commercial bolus of the same thickness, the visualized thermosensitive color-changing bolus shows a more effective dosimetric distribution in terms of target coverage, HI, and CI, a higher fit to the skin, highly visualized air cavity, and higher positional repeatability in fractionated radiotherapy, demonstrating high practicality and safety.
7.Research progress on discharge readiness in patients receiving home nutrition support
Xiao-Xuan XU ; Chu-Lin CHEN ; Qian DONG ; Meng LIU ; Fu-Ping WANG ; Dong-Mei ZHU
Parenteral & Enteral Nutrition 2025;32(2):119-123
Readiness for Hospital Discharge(RHD)refers to a multidimensional assessment of a patient's ability to transition safely from hospital to home,encompassing physiological stability,psychological preparedness,and social support adequacy.For patients requiring Home Nutrition Support(HNS),discharge readiness is particularly critical due to their heightened need for post-discharge specialized care,which significantly influences long-term recovery and quality of life.This paper reviews the concept,influencing factors,and unmet needs of RHD in patients with HNS and proposes targeted strategies to enhance discharge preparedness.By addressing gaps in current practices,we aim to optimize RHD in this vulnerable population and provide clinicians with evidence-based guidance for developing effective discharge plans.
8.Consensus on diagnosis and treatment of adolescent idiopathic scoliosis
Yushu BAI ; Kai CHEN ; Jie SHAO ; Xiao ZHAI ; Ming CHEN ; Weishi LI ; Jianzhong XU ; Bangping QIAN ; Zezhang ZHU ; Feng ZHU ; Chunde LI ; Jianguo ZHANG ; Jianxiong SHEN ; Dingjun HAO ; Xiaodong ZHU ; Junlin YANG ; Xuejun ZHANG ; Xuesong ZHANG ; Fangyi ZHANG ; Qijie WANG ; Wenzhi ZHANG ; Yong HAI ; Jianhua ZHAO ; Yong QIU ; Yan WANG ; Guixing QIU ; Ming LI
Academic Journal of Naval Medical University 2025;46(3):291-300
Adolescent idiopathic scoliosis(AIS)is a complex three-dimensional deformity involving coronal,sagittal,and axial planes,with a prevalence that should not be overlooked.With advancements in technology and in-depth research,an increasing number of hospitals and physicians are exploring standardized diagnostic and treatment approaches for AIS.Comprehensive and in-depth understanding is required for AIS,including its etiology,screening and diagnosis,classification,assessment and examination,treatment options,exploration of current focus,and evaluation of quality of life.Such understanding ensures that the diagnostic and treatment are scientific,standardized,and timely.Based on the principles of evidence-based medicine,a consensus on the diagnosis and treatment of AIS is reached after multiple discussions among spinal surgery experts,aiming to provide reference and guidance for clinical practice.
9.Effect of triglyceride-glucose index on short-term prognosis of patients with initial acute ischemic stroke
Jingfeng WANG ; Qinrong XU ; Hongxuan FENG ; Ruiyao HU ; Bodun MA ; Xiaotian YU ; Xiaofeng DONG ; Qian GUI ; Guanhui WU ; Hao ZHU
Academic Journal of Naval Medical University 2025;46(9):1121-1126
Objective To investigate the effect of triglyceride-glucose index(TyG)on the short-term prognosis of patients with initial acute ischemic stroke.Methods A total of 391 patients with initial acute ischemic stroke who were hospitalized in Kunshan Second People's Hospital and The Affiliated Suzhou Hospital of Nanjing Medical University from Jun.2020 to Jun.2023 were retrospectively included.According to the modified Rankin scale(mRS)scores at 90 d follow-up,they were assigned to good prognosis group(286 cases)or poor prognosis group(105 cases).Logistic regression and receiver operating characteristic(ROC)curve were used to evaluate the effect of TyG on the short-term prognosis of patients with initial acute ischemic stroke.Results Compared with the good prognosis group,the patients of poor prognosis group had older age,higher proportion of atrial fibrillation,higher levels of homocysteine,triglyceride,total cholesterol,low-density lipoprotein,and TyG,and higher National Institutes of Health stroke scale(NIHSS)score(all P<0.05).Multivariate logistic regression analysis showed that age,homocysteine,TyG and NIHSS score were independent risk factors for poor prognosis in patients with initial acute ischemic stroke(all P<0.05).ROC curve analysis showed that TyG combined with NIHSS score had good predictive value for poor prognosis of patients with initial acute ischemic stroke,and the area under curve value was 0.795.Conclusion The combination of TyG and NIHSS score is an independent influencing factor for poor short-term prognosis in patients with initial acute ischemic stroke.
10.Compound Xishu Granules Inhibit Proliferation of Hepatocellular Carcinoma Cells by Regulating Ferroptosis
Yuan TIAN ; Yuxi WANG ; Zhen LIU ; Yuncheng MA ; Hongyu ZHU ; Xiaozhu WANG ; Qian LI ; Jian GAO ; Weiling WANG ; Wenhui XU ; Ting WANG
Chinese Journal of Experimental Traditional Medical Formulae 2025;31(2):37-45
ObjectiveTo study the mechanism of compound Xishu granules (CXG) in inhibiting the proliferation of hepatocellular carcinoma cells by regulating ferroptosis. MethodsThe transplanted tumor model of human Huh7 was established with nude mice and the successfully modeled mice were randomized into model, Fufang Banmao (0.21 g·kg-1), low-dose (1.87 g·kg-1) CXG, medium-dose (3.74 g·kg-1) CXG, and high-dose (7.49 g·kg-1) CXG groups. Mice were administrated with drinking water or CXG for 28 days, and the body weight and tumor volume were measured every 4 days. Hematoxylin-eosin staining was employed to observe the histopathological changes of tumors. The cell-counting kit-8 (CCK-8) was used to examine the survival rate of Huh7 cells treated with different concentrations (0, 31.25, 62.5, 125, 250, 500, 1 000 mg·L-1) of CXG for 24 h and 48 h. CA-AM, DCFH-DA, and C11-BODIPY581/591 fluorescent probes were used to determine the intracellular levels of ferrous ion (Fe2+), reactive oxygen species (ROS), and lipid peroxide (LPO), respectively. The colorimetric method was employed to measure the levels of glutathione (GSH) and superoxide dismutase (SOD). Western blot was employed to determine the protein levels of glutathione peroxidase 4 (GPX4), transferrin receptor 1 (TFR1), and ferritin heavy chain 1 (FTH1), respectively. ResultsIn the animal experiment, compared with the model group, the drug treatment groups showed reductions in the tumor volume from day 12 (P<0.01). After treatment, the Fufang Banmao and low-, medium-, and high-dose CXG groups had lower tumor volume, relative tumor volume, and tumor weight than the model group (P<0.05), with tumor inhibition rates of 48.99%, 79.93%, 91.38%, and 97.36%, respectively. Moreover, the CXG groups had lower tumor volume and relative tumor volume (P<0.05 in all the three dose groups) and lower tumor weight (P<0.05 in medium-dose and high-dose groups) than the Fufang Banmao group. Compared with the model group, the drug treatment groups showed reduced number of tumor cells, necrotic foci with karyopyknosis, nuclear fragmentation, and nucleolysis, and the high-dose CXG group showed an increase in the proportion of interstitial fibroblasts. In the cell experiment, compared with the blank group, CXG reduced the survival rate of Huh7 cells in a dose-dependent manner after incubation for 24 h and 48 h (P<0.05). Compared with the blank group, the RSL3 group and the low-, medium-, and high-dose CXG groups showed a decrease in the relative fluorescence intensity of CA-AM and increases in the fluorescence intensity of DCFH-DA and fluorescence ratio of C11-BODIPY581/591, which indicated elevations in the levels of Fe2+ (P<0.01), ROS (P<0.05), and LPO (P<0.01), respectively. Compared with the blank group, the RSL3 and low-, medium-, and high-dose CXG groups showed lowered levels of GSH and SOD (P<0.05). In addition, the RSL3 group and the medium- and high-dose CXG groups showed down-regulated expression of GPX4 and FTH1 (P<0.05), and the low- and high-dose CXG groups presented up-regulated expression of TFR1 (P<0.05). ConclusionCXG suppresses the proliferation of hepatocellular carcinoma cells by inducing ferroptosis via downregulating the GSH-GPX4 signaling axis and increasing intracellular Fe2+and LPO levels.


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