[Analysis of Risk Factors of Chronic Pulmonary Heart Disease in Patients With Pneumoconiosis]. / å°˜è‚ºç— æ‚£è€ å‘ç”Ÿæ ¢æ€§è‚ºå¿ƒç— çš„å±é™©å› ç´ åˆ†æž.

Objective: To explore the risk factors for developing chronic pulmonary heart disease in patients with pneumoconiosis. Methods: The medical records of pneumoconiosis patients admitted to an occupational disease hospital in Sichuan Province between January 2012 and November 2021 were collected. Kaplan-Meier (K-M) method, or product-limit method, was used to plot the incidence curves of pulmonary heart disease in the pneumoconiosis patients. Cox proportional hazard regression model was used to analyze the influencing factors associated with chronic pulmonary heart disease in patients with pneumoconiosis. Results: A total of 885 pneumoconiosis patients were included in this study. The follow-up time was 12 to 115 months and the median follow-up time was 43 months. A total of 138 patients developed chronic pulmonary heart disease and the incidence density of pulmonary heart disease was 38.50/1000 person-years. Multivariate Cox proportional hazard regression analysis showed that the influencing factors of pneumoconiosis inpatients developing chronic pulmonary heart disease included the following, being 50 and older (hazard ratio [HR]=1.85, 95% confidence interval [CI]: 1.25-2.74), stage Ⅲ pneumoconiosis (HR=2.43, 95% CI: 1.48-4.01), resting heart rate≥100 beats/min (HR=2.62, 95% CI: 1.63-4.21), the complication of chronic obstructive pulmonary disease (COPD) (HR=4.52, 95% CI: 2.12-9.63), underweight (HR=2.40, 95% CI: 1.48-3.87), overweight and obesity (HR=0.54, 95% CI: 0.34-0.86), and triacylglycerol (TG) (HR=0.69, 95% CI: 0.49-0.99). Conclusion: Old age, stage Ⅲ pneumoconiosis, high resting heart rate, low BMI, and the complication of COPD are risk factors for chronic pulmonary heart disease in pneumoconiosis patients, while overweight and obesity and TG are protective factors. Early identification of the risk factors and the adoption of the corresponding prevention measures are the key to preventing chronic pulmonary heart disease in patients with pneumoconiosis.

The global dynamic transmissibility of COVID-19 and its influencing factors: an analysis of control measures from 176 countries.

OBJECTIVE: To summarise the dynamic characteristics of COVID-19 transmissibility; To analyse and quantify the effect of control measures on controlling the transmissibility of COVID-19; To predict and compare the effectiveness of different control measures. METHODS: We used the basic reproduction number ([Formula: see text]) to measure the transmissibility of COVID-19, the transmissibility of COVID-19 and control measures of 176 countries and regions from January 1, 2020 to May 14, 2022 were included in the study. The dynamic characteristics of COVID-19 transmissibility were summarised through descriptive research and a Dynamic Bayesian Network (DBN) model was constructed to quantify the effect of control measures on controlling the transmissibility of COVID-19. RESULTS: The results show that the spatial transmissibility of COVID-19 is high in Asia, Europe and Africa, the temporal transmissibility of COVID-19 increases with the epidemic of Beta and Omicron strains. Dynamic Bayesian Network (DBN) model shows that the transmissibility of COVID-19 is negatively correlated with control measures. Restricting population mobility has the strongest effect, nucleic acid testing (NAT) has a strong effect, and vaccination has the weakest effect. CONCLUSION: Strict control measures are essential for controlling the COVID-19 outbreak; Restricting population mobility and nucleic acid testing (NAT) have significant impacts on controlling the COVID-19 transmissibility, while vaccination has no significant impact. In light of these findings, future control measures may include the widespread use of new NAT technology and the promotion of booster immunization.

The development and evaluation of the worker-occupation fit inventory.

BACKGROUND: Person-environment fit (PEF) theory, one of the foundational theories of occupational stress, has primarily found applications in organizational behavior and human resource management. Given the alignment between the definition of occupational stress and the essence of PEF, we introduced the concept of worker-occupation fit (WOF). To validate our theoretical model, the development of an instrument to measure WOF becomes imperative. METHODS: The Worker-Occupation Fit Inventory (WOFI) comprises three dimensions: personal trait fit (PTF), need-supply fit (NSF) and demand-ability fit (DAF). Job-related mental disorders (JRMDs) were assessed using the DASS-21. During the pre-investigation, items of the WOFI underwent screening through classic test theory (CTT) analysis. In the formal investigation, item response theory (IRT) analysis was employed to evaluate the selected items. The relationship between WOF and JRMD was verified by Pearson's correlation analysis and multiple logistic regression analysis. RESULTS: The initial version consisted of 26 items. Three common factors were extracted by exploratory factor analysis (EFA): 6 items were included in the PTF, 6 items were included in the NSF, 4 items were included in the DAF, and 10 items were deleted because of unacceptable factor loadings. The confirmatory factor analysis (CFA) verified the structure of the WOFI with χ2/df = 1.822, CFI = 0.947, and SRMSR = 0.056. The Cronbach's alpha coefficients of the PTF, NSF, and DAF were 0.91, 0.92, and 0.80, respectively. In IRT analysis, the discrimination values of all items ranged from 1.25 to 2.53, and the difficulty values of all items ranged from -6.28 to 1.30 (with no difficulty of reversal). The WOF was negatively related to job-related stress (r = -0.34, p<0.001), anxiety (r = -0.37, p<0.001), and depression (r = -0.41, p<0.001). The multiple logistic regression analysis suggested that a high level of WOF was a protective factor against job-related mental disorders, with ORs all less than 1 (p<0.001), and a low level of WOF was a risk factor for job-related mental disorders, with ORs all more than 1.0 (p<0.001). CONCLUSIONS: The results of CTT and IRT analysis indicated that the WOFI exhibits reliability and validation. The WOF effectively predicted job-related mental disorders. Subsequent studies will delve into the influence of WOFI on diverse professions and various health outcomes.

Epidemiological features of SARS-CoV-2 Omicron infection under new control strategy: a cross-sectional study of the outbreak since December 2022 in Sichuan, China.

BACKGROUND: A major shift in the "dynamic zero-COVID" policy was announced by China's National Health Commission on December 7, 2022, and the subsequent immediate large-scale outbreak of SARS-CoV-2 infections in the entire country has caused worldwide concern. This observational cross-sectional study aimed to describe the epidemiological characteristics of this outbreak in Sichuan, China. METHODS: All data were self-reported online by volunteers. We described the epidemic by characterizing the infection, symptoms, clinical duration, severity, spatiotemporal clustering, and dynamic features of the disease. Prevalence ratio (PR), Odds ratios (ORs) and adjusted ORs were calculated to analyze the associations between risk factors and infection and the associations of risk factors with clinical severity using log-binomial and multivariable logistic regression models; 95% confidence intervals (CIs) and Wald test results were reported. The prevalence rates and clinical severity among different subgroups were compared using the Chi-square and trend Chi-square tests. RESULTS: Between January 6 and 12, 2023, 138,073 volunteers were enrolled in this survey, and 102,645 were infected with COVID-19, holding a prevalence rate of 74.34%; the proportion of asymptomatic infections was 1.58%. Log-binomial regression revealed that the risk of infection increased among those living in urban areas. Multivariable logistic regression analysis showed that female sex, chronic diseases, older age and the fewer doses of vaccine received were associated with an increased risk of severe clinical outcomes after infection. We estimated the mean reproduction number during this pandemic was 1.83. The highest time-dependent reproduction number was 4.15; this number decreased below 1 after 11 days from December 7, 2022. Temporal trends revealed a single peak curve with a plateau pattern of incidence during the outbreak, whereas spatiotemporal clustering analysis showed that the onset in 21 cities in the Sichuan province had four-wave peaks. CONCLUSIONS: The peak of the first wave of Omicron infection in Sichuan Province had passed and could be considered a snapshot of China under the new control strategy. There were significant increases in the risk of severe clinical outcomes after infection among females, with chronic diseases, and the elderly. The vaccines have been effective in reducing poor clinical outcomes.

Virus-virus interactions of febrile respiratory syndrome among patients in China based on surveillance data from February 2011 to December 2020.

The burden of acute respiratory infections is still considerable, and virus-virus interactions may affect their epidemics, but previous evidence is inconclusive. To quantitatively investigate the interactions among respiratory viruses at both the population and individual levels, we use data from the pathogen surveillance for febrile respiratory syndrome (FRS) in China from February 2011 to December 2020. Cases tested for influenza virus (IV), respiratory syncytial virus (RSV), human parainfluenza virus (PIV), human Adenovirus (AdV), human coronavirus (CoV), human bocavirus (BoV), and rhinovirus (RV) were collected. We used spearman's rank correlation coefficients and binary logistic regression models to analyze the interactions between any two of the viruses at the population and individual levels, respectively. Among 120 237 cases, 4.5% were coinfected with two or more viruses. Correlation coefficients showed seven virus pairs were positively correlated, namely: IV and RSV, PIV and AdV, PIV and CoV, PIV and BoV, PIV and RV, AdV and BoV, and CoV and RV. Regression models showed positive interactions for all virus pairs, except for the negative interaction between IV and RV (odds ratio = 0.70, 95% confidence interval: 0.61-0.81). Most of the respiratory viruses interact positively, while IV and RV interact negatively.

Identifying the risk features for occupational stress in medical workers: a cross-sectional study.

OBJECTIVE: Occupational stress is considered a worldwide epidemic experienced by a large proportion of the working population. The identification of characteristics that place people at high risk for occupational stress is the basis of managing and intervening in this condition. In this study, we aimed to identify and validate the risk features for occupational stress among medical workers using a risk model and nomogram. METHODS: This cross-sectional study included 1988 eligible participants from Henan Province in China. Occupational stress and worker-occupation fit were measured with the Depression, Anxiety and Stress Scales (DASS-21) and Worker-Occupation Fit Inventory (WOFI). The identification of risk features was achieved through constructing multiple logistic regression model, and the risk features were used to develop the risk model and nomogram. Receiver operating characteristic (ROC) curves and calibration plots were generated to assess the effectiveness and calibration of the risk model. RESULTS: Among 1988 participants in our study, there were 42.5% (845/1988) medical workers experienced occupational stress. The risk features for occupational stress included poor work-occupation fit (WOF score < 25, expected risk: 77.3%), nurse population (expected risk: 63.1%), male sex (expected risk: 67.2%), work experience duration of 11-19 years (expected risk: 54.5%), experience of a traumatic event (expected risk: 65.3%) and the lack of a regular exercise habit (expected risk: 60.2%). For medical workers who have these risk features, the expected risk probability of occupational stress would be 90.2%. CONCLUSION: The current data can be used to identify medical workers at risk of developing occupational stress. Identifying risk features for occupational stress and the work-occupation fit can support hierarchical stress management in hospitals.

A risk model and nomogram for high-frequency hearing loss in noise-exposed workers.

BACKGROUND: High-frequency hearing loss is a significant occupational health concern in many countries, and early identification can be effective for preventing hearing loss. The study aims to construct and validate a risk model for HFHL, and develop a nomogram for predicting the individual risk in noise-exposed workers. METHODS: The current research used archival data from the National Key Occupational Diseases Survey-Sichuan conducted in China from 2014 to 2017. A total of 32,121 noise-exposed workers completed the survey, of whom 80% workers (n = 25,732) comprised the training cohort for risk model development and 20% workers (n = 6389) constituted the validation cohort for model validation. The risk model and nomogram were constructed using binary logistic models. The effectiveness and calibration of the model were evaluated with the receiver operating characteristic curve and calibration plots, respectively. RESULTS: A total of 10.06% of noise-exposed workers had HFHL. Age (OR = 1.09, 95% CI: 1.083-1.104), male sex (OR = 3.25, 95% CI: 2.85-3.702), noise exposure duration (NED) (OR = 1.15, 95% CI: 1.093-1.201), and a history of working in manufacturing (OR = 1.50, 95% CI: 1.314-1.713), construction (OR = 2.29, 95% CI: 1.531-3.421), mining (OR = 2.63, 95% CI: 2.238-3.081), or for a private-owned enterprise (POE) (OR = 1.33, 95% CI: 1.202-1.476) were associated with an increased risk of HFHL (P < 0.05). CONCLUSIONS: The risk model and nomogram for HFHL can be used in application-oriented research on the prevention and management of HFHL in workplaces with high levels of noise exposure.

Dynamic prediction for clinically relevant pancreatic fistula: a novel prediction model for laparoscopic pancreaticoduodenectomy.

BACKGROUND: With the recent emerge of dynamic prediction model on the use of diabetes, cardiovascular diseases and renal failure, and its advantage of providing timely predicted results according to the fluctuation of the condition of the patients, we aim to develop a dynamic prediction model with its corresponding risk assessment chart for clinically relevant postoperative pancreatic fistula after laparoscopic pancreaticoduodenectomy by combining baseline factors and postoperative time-relevant drainage fluid amylase level and C-reactive protein-to-albumin ratio. METHODS: We collected data of 251 patients undergoing LPD at West China Hospital of Sichuan University from January 2016 to April 2019. We extracted preoperative and intraoperative baseline factors and time-window of postoperative drainage fluid amylase and C-reactive protein-to-albumin ratio relevant to clinically relevant pancreatic fistula by performing univariate and multivariate analyses, developing a time-relevant logistic model with the evaluation of its discrimination ability. We also established a risk assessment chart in each time-point. RESULTS: The proportion of the patients who developed clinically relevant postoperative pancreatic fistula after laparoscopic pancreaticoduodenectomy was 7.6% (19/251); preoperative albumin and creatine levels, as well as drainage fluid amylase and C-reactive protein-to-albumin ratio on postoperative days 2, 3, and 5, were the independent risk factors for clinically relevant postoperative pancreatic fistula. The cut-off points of the prediction value of each time-relevant logistic model were 14.0% (sensitivity: 81.9%, specificity: 86.5%), 8.3% (sensitivity: 85.7%, specificity: 79.1%), and 7.4% (sensitivity: 76.9%, specificity: 85.9%) on postoperative days 2, 3, and 5, respectively, the area under the receiver operating characteristic curve was 0.866 (95% CI 0.737-0.996), 0.896 (95% CI 0.814-0.978), and 0.888 (95% CI 0.806-0.971), respectively. CONCLUSIONS: The dynamic prediction model for clinically relevant postoperative pancreatic fistula has a good to very good discriminative ability and predictive accuracy. Patients whose predictive values were above 14.0%, 8.3%, and 7.5% on postoperative days 2, 3, and 5 would be very likely to develop clinically relevant postoperative pancreatic fistula after laparoscopic pancreaticoduodenectomy.

Association between insomnia and job stress: a meta-analysis.

PURPOSE: Insomnia has become one of the foremost health concerns among workers. Despite a significant number of epidemiological studies have reported on the correlation between insomnia and job stress, comprehensive evidence remains insufficient. Therefore, this research seeks to provide evidence with greater reliability, through summarizing relevant contemporary literature via a meta-analysis. METHODS: Literature from across Europe and Asia that was of both a prospective and cross-sectional design was included, if well-controlled odds ratios were available. The meta-analysis was undertaken in accordance with the guidelines devised by PRISMA, including tests for publication bias and heterogeneity. RESULTS: High job stress was associated with a greater risk of suffering from insomnia (random OR = 1.73, 95% CI 1.46-2.05), and the correlation between effort-reward imbalance and insomnia was statistically significant (random OR = 2.63, 95% CI 1.22-5.69). Higher demand was correlated to a relatively greater risk of insomnia (random OR = 1.35, 95% CI 1.20-1.51), while the pooled effect of low control was not found to be statistically significant. The summary random odds ratio of heavy workload was 2.76, and a pooled odds ratio of 1.67 (fixed, 95% CI 1.11-2.52) was calculated in low social support. With regard to the overall population, work-family conflict was correlated with insomnia (random OR = 2.32, 95% CI 1.53-3.51). The subgroup analysis provided comparable outcomes, for both males (fixed OR = 1.97, 95% CI 1.50-2.57) and females (random OR = 2.80, 95% CI 1.30-6.05). Egger's regression indicated that publication bias may be apparent in the syntheses of effort-reward imbalance, low social support, and work-family conflict (p < 0.05). Heterogeneity was caused by design, measuring the exposure or outcome, in addition to the region where the research was conducted. CONCLUSIONS: The correlation between insomnia and higher levels of job stress, effort-reward imbalance, high demand, heavy workload, and low social support was determined. Publication bias and heterogeneity were partially observed. Furthermore, future studies with improved methodologies and a focus on mechanisms are anticipated.

Viral pathogens among elderly people with acute respiratory infections in Shanghai, China: Preliminary results from a laboratory-based surveillance, 2012-2015.

Acute respiratory infections (ARIs), with viral pathogens as the major contributors, are the most common illnesses worldwide, and increase the morbidity and mortality among the elderly population. The clinical and pathological features of elderly people with ARIs need to be identified for disease intervention. From January 1, 2012 through December 31, 2015, respiratory specimens from patients above 60 years old with ARIs were collected from the outpatient and inpatient settings of six sentinel hospitals in Pudong New Area. Each specimen was tested via multiplex polymerase chain reaction (PCR) for eight target viral etiologies including influenza, human rhinovirus (HRV), human para-influenza virus (PIV), adenovirus (ADV), respiratory syncytial virus (RSV), human metapneumovirus (hMPV), human coronavirus (hCoVs), and human bocavirus (hBoV). A total of 967 elderly patients with ARIs were enrolled, including 589 (60.91%) males, and the median age was 73 years old. 306 (31.64%) patients were tested positive for any one of the eight viruses, including 276 single infections and 30 co-infections. Influenza was the predominant virus (14.17%, 137/967), detected from 21.35% (76/356) of the outpatients and 9.98% (61/611) of the inpatients. Influenza infections presented two annual seasonal peaks during winter and summer. Compared with non-influenza patients, those with influenza were more likely to have fever, cough, sore throat, and fatigue. This study identified influenza as the leading viral pathogen among elderly with ARIs, and two seasonal epidemic peaks were observed in Shanghai. An influenza vaccination strategy needs to be advocated for the elderly population.

[The Relationship of Polymorphisms in Interleukin 17A Gene, Interleukin 17F Gene and the Pulmonary Inflammation Risk in Dust Exposed Workers in a Chinese Population].

OBJECTIVES: To investigate the polymorphisms in interleukin 17A IL-17A) and interleukin 17F (IL-17F) and their relationship with pulmonary inflammation risk of dust exposed workers. METHODS: A case-control study among 193 subjects, including 67 subjects in case group and 126 in control group was conducted. PCR-RFLP was applied to genotype IL-17A (G-197A) and IL-17F (7488T/C). Logistic regression analysis was used to determine the effects of IL-17A (G-197A) and IL-17F (7488T/C) on the lung inflammation risk in dust exposed workers. RESULTS: The genotypes analysis showed that the proportions of IL-17A (G-197A) A/A, A/G and G/G were 42 (21.76%), 95 (49.22%), 56 (29.02%) in 193 cases, respectively, and the IL-17F (7488T/C) T/T, T/C and C/C genotypes were 128 (66.32%), 54 (28.98%), 11 (5.70%), respectively. The frequency distribution of each genotype was consistent with the Hardy-Weinberg equilibrium fixed law. The ratio of IL-17A (G-197A) A/A in the case group was lower than that of control group ( P<0.05), while the G/G and A/G genotypes were higher than that of control group ( P<0.05). Furthermore, the genotypes of IL-17A (G-197A) A/G (OR=5.03, P<0.01) and G/G(OR=3.35, P<0.05) were associated with an increased risk of lung inflammation in workers exposed to dust. The frequency distribution difference of IL-17F (7488T/C) T/T, T/C and C/C genotypes in the cases and control group was unobvious ( P>0.05). CONCLUSIONS: Under the same dust concentration, the dust exposed workers carrying IL-17A (G-197A) A/G, G/G genotypes are more susceptible to pulmonary inflammation in the southwest of China.

[Application and evaluation of signal strength indictor in communicable disease automatic early warning system].

OBJECTIVE: To explore the effect of signal strength indictor (SSI) in improving sensitivity of China Infectious Diseases Automated-alert and Response System (CIDARS). METHODS: Diarrhea cases in 2007-2011 and early warning signals in 2010-2011 were selected by using random digital table method. Then, SSI and event-related ratio (ER) were calculated. The relationship between ER and SSI was analyzed, and the effect of SSI on ER was explored by using multiple logistic regression analysis. RESULTS: 9 620 early warning signals in 2010-2011 were generated in two years. Of these, 74, or 0.77% were defined as suspected outbreak signal. The median of SSI related with suspected outbreak signal was 4.0, which was much higher than non-suspected outbreak signal (1.7). ER was significantly correlated with SSI (r=0.917). SSI classification has a good correlation between the ER, ER exceeded 20 after SSI reached 20. The multivariate logistic regression analysis showed OR of SSI related with suspected outbreak signal was 2.52 (95% CI 2.04-3.12). Compared with non-epidemic season, the relationship of SSI and ER in epidemic season was much higher. CONCLUSION: SSI was closely related with ER. The relationship was much closer in large scale outbreak and epidemic season, and compared to non-epidemic,the effect of epidemic season is more obvious.

[Interaction Between Occupational Vanadium Exposure and hsp70-hom on Neurobehavioral Function].

OBJECTIVE: In determine the effect of heat shock protein 70-hom gene (hsp70-hom) polymorphism on the neurobehavioral function of workers exposed to vanadium. METHODS: Workers from the vanadium products and chemical industry were recruited by cluster sampling. Demographic data and exposure information were collected using a questionnaire. Neurobehavioral function was assessed by Neurobehavioral Core Test Battery. The hsp70-hom genotype was detected by restricted fragment length polymorphism-polymerase chain reaction (RFLP-PCR). A neurobehavioral index (NBI) was formulated through principal component analysis. RESULTS: Workers with a T/C genotype had worse performance in average reaction time, visual retention, digital span (backward), Santa Ana aiming (non-habitual hand), pursuit aiming (right points, total points), digit symbol and NBI score than others (P < 0.05). The relative risk of abnormal NBI score of the workers with a T/C genotype was 1.748 fold of those with a T/T genotype. The relative risk of abnormal.NBI score of the workers exposed to vanadium was 3.048 fold of controls (P < 0.05). But after adjustment with age and education, only vanadium exposure appeared with a significant effect on NBI score. When gene polymorphism and vanadium exposure coexisted, the effect of vanadium on neurobehavioral function was attenuated, but the influence of T/C genotype increased Codds ratio (OR = 4.577, P < 0.05). After adjustment with age and education, the OR of T/C genotype further increased to 7.777 (P < 0.05). Vanadium exposure and T/C genotype had.a bio-interaction effect on NBI score Crelative excess risk due to interaction (RERI) = 4.12, attributable proportion (AP) = 0.7, synergy index (S) = 6.45]. After adjustment with age and education, the RERI became 2.49 and the AP became 0.75, but no coefficient of interaction was produced. CONCLUSION: Priorities of occupational protection should be given to vanadium-exposed workers with a hsp70-hom T/C genotype and low education level.

A cross-sectional study on the relationships among the polymorphism of period2 gene, work stress, and insomnia.

PURPOSE: Work-related stress factors are commonly considered to be increasing the risk of insomnia. But the association between circadian-rhythm gene period2 (per2) and insomnia remains unknown. The paper aimed to examine the relationships among the polymorphism in rs7602358 of Per2 gene, work stress, and insomnia. METHODS: In the cross-sectional study of a total of 364 Chinese workers recruited, 218 had insomnia tested by the Athens Insomnia Scale (AIS-5). Work stress was assessed using the General Job Stress Questionnaire (GJSQ). Per2 genotypes were determined by SNaPshot technology. Unconditional logistic regression analysis was used to examine the interaction between polymorphism of Per2 and work stress in insomnia. RESULTS: The genotype AC or allele C of Per2 significantly increased the risk of insomnia (OR, 5.41; 95 % CI, 2.23-13.1) (OR, 3.29; 95 % CI, 1.55-6.98). Compared to low work stress, high work stress had a higher risk of insomnia (OR, 2.73; 95 % CI, 1.77-4.22). A significant interaction between Per2 and work stress in the risk of insomnia was found. Compared to workers with low work stress and genotype AA, those with high work stress and genotype AC had a higher risk of insomnia (OR, 15.12; 95 % CI, 3.46-66.09). CONCLUSIONS: The effect of genotype AC or allele C of Per2 on insomnia was relatively stronger than that of high work stress, suggesting that individual's susceptibility should be taken into consideration when intervening and controlling insomnia of workers.

[Distribution and main influential factors of mental workload of middle school teachers in Nanchang City].

OBJECTIVE: To investigate the distribution and main influential factors of mental workload of middle school teachers in Nanchang City. METHODS: A total of 504 middle school teachers were sampled by random cluster sampling from middle schools in Nanchang City, and the mental workload level was assessed with National Aeronautics and Space Administration-Task Load Index (NASA-TLX) which was verified in reliability and validity. RESULTS: The mental workload scores of middle school teachers in Nanchang was approximately normal distribution. The mental workload level of middle school teachers aged 31 -35 years old was the highest. For those no more than 35 years old, there was positive correlation between mental workload and age (r = 0.146, P < 0.05). For those more than 35 years old, the levels of their mental workload had no statistically significant difference. There was a negative correlation between mental workload and educational level(r = -0.172, P < 0.05). The middle school teachers with lower educational level seemed to have a higher mental workload (P < 0.01). The longer a middle school teacher worked per day, the higher the mental workload was. Working hours per day was the most influential factor on mental workload in all influential factors (P < 0.001). CONCLUSION: Mental workload of middle school teachers was closely related to age, educational level and work hours per day. Working hours per day was the important risk factor of mental workload. Reducing working hours per day, especially reducing it to be no more than 8 hours per day, may be a significant and useful approach alleviating mental workload of middle school teachers in Nanchang City.

[Oxidative Stress Level of Vanadium-exposed Workers].

OBJECTIVE: To determine the oxidative stress level in peripheral blood of vanadium-exposed workers, as an indication of population health effect of vanadium on human neurobehavioral system. METHODS: 86 vanadium-exposed workers and 65 non-exposed workers were recruited by cluster sampling. A questionnaire was administered to collect demographic and occupational exposure information. Serum activity of superoxide dismutase (SOD), inducible nitric oxide synthase (iNOS) and malonaldehyde (MDA) contents were detected by kit assay. The differences in oxidative stress level between vanadium-exposed and non-exposed workers were compared. RESULTS: Vanadium-exposed workers had higher levels of MDA contents than the controls. The total superoxide dismutase(T-SOD) activity in vanadium-exposed workers was significantly lower than that in the controls, which was associated with lowered levels of manganese superoxide dismutase (Mn-SOD) activity. No changes in serum levels of cupro-zinc superoxide dismutase (CuZn-SOD) was found in vanadium-exposed workers. No difference in iNOS activity was found between vanadium-exposed workers and controls. CONCLUSION: Vanadium exposure increases free radical production in serum and reduces antioxidant capacity. But the relationship between vanadium exposure and iNOS damage remains uncertain.

[A study of relationship between occupational stress and diseases in secondary school teachers].

OBJECTIVE: To analyze the relationship between occupational stress and diseases in secondary school teachers in a city of Sichuan Province, and to provide a basis for the evaluation of the long-term effects of occupational stress in teachers. METHODS: With secondary school teachers as the target population, the stratified cluster sampling was adopted to conduct three studies among 780, 119, and 689 secondary school teachers in a city of Sichuan Province in 1999, 2005, and 2009, respectively. The Occupational Stress Inventory-Revised Edition (OSI-R) and working ability index (WAI) were used to investigate occupational stress and diseases in secondary school teachers. The variation of occupational stress in secondary school teachers was compared between different periods and the relationship between the intensity of stress and diseases was evaluated, on the basis of which the variation of the relationship over time was analyzed. RESULTS: There were significant differences in occupational stress in secondary school teachers between different periods (P<0.05). The incidence rates of medium and high physiological stress and psychological stress were significantly higher in 2009 than in 1999 (P<0.05). Compared with the year of 1999, the intensity of occupational stress in 2009 changed with cardiovascular, respiratory, and mental diseases. The incidence of abnormal psychological stress was a risk factor for all chronic, respiratory, and mental diseases (OR: 1.88, 2.25, and 5.91). The time dependence of odds ratio was only found in the risk of respiratory diseases: occupational stress resulted in a significant increase in the risk of respiratory diseases over time (P<0.05). Physiological stress was a risk factor for mental diseases (OR=2.31). CONCLUSION: The intensity of occupational stress in secondary school teachers changes over time. Occupational stress elevates the risks of certain diseases and has a time-dependent effect on the risk of respiratory diseases. Occupational stress in secondary school teachers needs more attention and effective prevention.

[A multilevel model analysis of correlation between population characteristics and work ability of employees].

OBJECTIVE: To analyze the correlation between population characteristics and work ability of employees with a multilevel model, to investigate the important influencing factors for work ability, and to provide a basis for improvement in work ability. METHODS: Work ability index (WAI)was applied to measure the work ability of 1686 subjects from different companies (n=6). MLwi N2.0 software was applied for two-level variance component model fitting. RESULTS: The WAI of employees showed differences between various companies (χ2=3.378 6, P=0.0660); working years was negatively correlated with WAI (χ2=38.229 2, P=0.0001), and the WAI of the employees with 20 or more working years was 1.63 lower than that of the employees with less than 20 working years; the work ability of manual workers was lower than that of mental-manual workers (χ2=8.2726, P=0.0040), and the work ability showed no significant difference between mental workers and mental-manual workers (χ2=2.086 0, P=0.148 7). CONCLUSION: From the perspective of probability, the multilevel model analysis reveals the differences in work ability of employees between different companies, and suggests that company, work type, and working years are the important influencing factors for work ability of employees. These factors should be improved and adjusted to protect or enhance the work ability of employees.

[Analysis of posttraumatic stress disorder in rescuers and firefighters].

OBJECTIVE: To investigate the occurrence and associated factors for posttraumatic stress disorder (PTSD) in rescuers and firefighters. METHODS: The PTSD of 264 rescuers and firefighters who had participated in rescue was evaluated using the self-designed fireman general situation questionnaire and PTSD Checklist-Civilian Version (PCL-C). The factors associated with the occurrence of PTSD were also analyzed. RESULTS: The incidence rate of PTSD in the subjects was 8.3%. The PTSD rate of special service corps (12%) was significantly higher than that of other subjects (P<0.05). The incidence of PTSD was highest in the rescuers and firefighters above the third rank, but without significant differences (P>0.05). The PTSD rate of married rescuers and firefighters was significantly higher than that of unmarried subjects (P<0.05). The PTSD rate of subjects addicted to drinking was significantly higher than that of non-drinking subjects (P<0.05). Subjects with more frequent attendance were more susceptible to PTSD compared with those with less attendance. CONCLUSION: The incidence rate of PTSD is high in rescuers and firefighters who have attended rescues. It is necessary to implement both short-term and long-term counseling programs for stress management and intervention in order to reduce the psychological trauma after rescue and improve the mental health of rescuers and firefighters.

[Relationship of personality with job burnout and psychological stress risk in clinicians].

OBJECTIVE: To analyze the job burnout and mental health status of clinicians and the relationship of personality with job burnout and psychological stress, and to investigate the direct or indirect effects of personality on psychological stress. METHODS: Maslach Burnout Inventory-General Survey (MBI-GS), Eysenck Personality Questionnaire-Revised Short Scale (EPQ-RSC), and Kessler 10 Scale were administered to 775 clinicians. RESULTS: Of all clinicians, 29.5% had mild burnout, with a score of 22.7 ± 8.18 for psychological stress risk. The effect of personality on emotional exhaustion and cynicism was greater than that on personal accomplishment. Clinicians with a personality of introversion, neuroticism, and psychoticism suffered a higher risk of psychological stress. Personality had both direct and indirect effects on psychological stress. Neuroticism had the strongest effect on psychological stress, with an effect size of 0.55. CONCLUSION: Clinicians have a high level of both job burnout and mental psychological stress risk. Personality is significantly correlated with job burnout and psychological stress risk. Measures depending on personality should be taken for effective intervention.