苏州市肺癌发病死亡与二氧化氮的关系研究*

目的探索大气二氧化氮(NO_2)对苏州市居民肺癌发病、死亡影响的程度和特点,确定滞后时间,评估健康效应。方法收集2006—2014年苏州市居民肺癌发病、死亡资料,大气污染物和气象数据,采用时间序列的广义相加模型,在控制长期趋势、星期几效应和气象因素的影响后,定量分析单污染物模型和双污染物模型中,大气NO_2对肺癌发病死亡人数的影响。结果单污染物模型中,滞后3天的NO_2(lag3)对肺癌日发病数的效应有统计学意义(P=0.03)。随着NO_2浓度每升高10μg/m~3,肺癌全人群和女性人群日发病数分别增加1.001%(95%CI:0.075,1.926)和2.541%(95%CI:0.744,4.338)。双污染物模型结果显示,NO_2对肺癌发病影响需要和PM2.5相互作用才发挥效应,不受SO_2和PM10的影响。结论苏州市肺癌,特别是女性肺癌发病人数随着大气NO_2浓度的增加而呈上升趋势;其影响存在滞后性,需要PM2.5的联合作用才能发挥效应。     

Short-term effects of ambient air pollutants on asthma-related emergency department visits in Indianapolis,Indiana, 2007–2011

Objective: We estimate the short-term associations between daily changes in ambient air pollutants and daily asthma-related emergency department (ED) visits in Indianapolis, IN. Methods: We identified asthma-related ED visits among Indianapolis residents aged ≥5 years. We used Poisson regression in a time-series framework to estimate the increased risk for asthma-related ED visits from exposure to ambient SO₂, PM_2.5 and ozone during the warm season (April–September) and SO₂ and PM_2.5 during the cold (October–March) season, from 2007 to 2011. Our models controlled for measured confounders, including weather and respiratory infections, as well as unmeasured confounders using a natural cubic spline to account for long-term seasonal trends. Results: During 2007–2011 in Indianapolis, 165?056 asthma-related ED visits occurred. We found statistically significant positive associations (p?<?0.05) between ambient air pollutants and ED visits during the warm season for persons aged 5–44 years. Interquartile range increases in daily ozone concentrations with same day, 2-day lagged, and 3-day moving average were associated with increased risks for ED visits of 3.2% (95% CI: 0.2%, 6.3%), 4.4% (0.1%, 8.9%) and 4.8% (0.2%, 9.6%), respectively. Interquartile range increases in 3-day moving averages for SO₂ were associated with an increased risk of 3.3% (95% CI: 0.2%, 6.5%). We identified statistically significant associations (p?<?0.05) between increased SO₂ and PM_2.5 levels and decreased ED visits among some age groups, primarily during the cold season, and no significant positive associations between changes in PM_2.5 concentration and asthma-related ED visits. Conclusions: During the warm season, increases in ozone and SO₂ concentrations were associated with increased asthma morbidity in children and young adults in Indianapolis. These results will enable reliable estimation of the health impacts of increases in these pollutants on asthma-related ED visits in Indianapolis and similar communities.     

Gender Effects Following Repeated Administration of Cocaine and Alcohol in Humans

Meta-analysis is applied to aggregate-level studies that model the demand for cigarettes using static, myopic, or rational addiction frameworks in an attempt to synthesize key findings in the literature and to identify determinants of the variation in reported price elasticity estimates across studies. The results suggest that the rational addiction framework produces statistically similar estimates to the static framework but that studies that use the myopic framework tend to report more elastic price effects. Studies that applied panel data techniques or controlled for cross-border smuggling reported more elastic price elasticity estimates, whereas the use of instrumental variable techniques and time trends or time dummy variables produced less elastic estimates. The finding that myopic models produce different estimates than either of the other two model frameworks underscores that careful attention must be given to time series properties of the data.     

Utensil Swab Test

The effectiveness of the utensil swab test as part of the periodic inspection of food establishments was studied both as an indicator of cleanliness during the period between inspections and as an educational tool.

Two to seven samplings were taken at intervals of two to three months at 95 food establishments in rural areas in the northern part of Israel. A statistical analysis showed a high variation and almost no correlation between repeated samplings of the same establishment. Also, no trend to suggest an educational effect was found. We concluded that, though the swab test had proved to be useful in special projects, it had no value as part of the periodic sanitary inspections.     

Effects of coarse particulate matter on emergency hospital admissions for respiratory diseases: a time-series analysis in Hong Kong

Background: Many epidemiological studies have linked daily counts of hospital admissions to particulate matter (PM) with an aerodynamic diameter ≤ 10 μm (PM₁₀) and ≤ 2.5 μm (PM_2.5), but relatively few have investigated the relationship of hospital admissions with coarse PM (PM_c; 2.5–10 μm aerodynamic diameter).Objectives: We conducted this study to estimate the health effects of PM_c on emergency hospital admissions for respiratory diseases in Hong Kong after controlling for PM_2.5 and gaseous pollutants.Methods: We conducted a time-series analysis of associations between daily emergency hospital admissions for respiratory diseases in Hong Kong from January 2000 to December 2005 and daily PM_2.5 and PM_c concentrations. We estimated PM_c concentrations by subtracting PM_2.5 from PM₁₀ measurements. We used generalized additive models to examine the relationship between PM_c (single- and multiday lagged exposures) and hospital admissions adjusted for time trends, weather conditions, influenza outbreaks, PM_2.5, and gaseous pollutants (nitrogen dioxide, sulfur dioxide, and ozone).Results: A 10.9-μg/m³ (interquartile range) increase in the 4-day moving average concentration of PM_c was associated with a 1.94% (95% confidence interval: 1.24%, 2.64%) increase in emergency hospital admissions for respiratory diseases that was attenuated but still significant after controlling for PM_2.5. Adjusting for gaseous pollutants and altering models assumptions had little influence on PM_c effect estimates.Conclusion: PM_c was associated with emergency hospital admissions for respiratory diseases in Hong Kong independent of PM_2.5 and gaseous pollutants. Further research is needed to evaluate health effects of different components of PM_c.     

Fine particulate matter constituents and cardiopulmonary mortality in a heavily polluted Chinese city

Background: Although ambient fine particulate matter (PM_2.5; particulate matter ≤ 2.5 µm in aerodynamic diameter) has been linked to adverse human health effects, the chemical constituents that cause harm are unknown. To our knowledge, the health effects of PM_2.5 constituents have not been reported for a developing country.Objectives: We examined the short-term association between PM_2.5 constituents and daily mortality in Xi’an, a heavily polluted Chinese city.Methods: We obtained daily mortality data and daily concentrations of PM_2.5, organic carbon (OC), elemental carbon (EC), and 10 water-soluble ions for 1 January 2004 through 31 December 2008. We also measured concentrations of fifteen elements 1 January 2006 through 31 December 2008. We analyzed the data using over-dispersed generalized linear Poisson models.Results: During the study period, the mean daily average concentration of PM_2.5 in Xi’an was 182.2 µg/m³. Major contributors to PM_2.5 mass included OC, EC, sulfate, nitrate, and ammonium. After adjustment for PM_2.5 mass, we found significant positive associations of total, cardiovascular, or respiratory mortality with OC, EC, ammonium, nitrate, chlorine ion, chlorine, and nickel for at least 1 lag day. Nitrate demonstrated stronger associations with total and cardiovascular mortality than PM_2.5 mass. For a 1-day lag, interquartile range increases in PM_2.5 mass and nitrate (114.9 and 15.4 µg/m³, respectively) were associated with 1.8% [95% confidence interval (CI): 0.8%, 2.8%] and 3.8% (95% CI: 1.7%, 5.9%) increases in total mortality.Conclusions: Our findings suggest that PM_2.5 constituents from the combustion of fossil fuel may have an appreciable influence on the health effects attributable to PM_2.5 in Xi’an.     

两组中断时间序列设计及其分析方法

中断时间序列（ITS）是对具有时间序列特点的结果变量进行分析,评价干预措施是否有效的类实验设计方法。相对于单组ITS,两组ITS可以更好地控制干预前混杂因素的影响,评价干预措施的效果。本文阐述两组ITS的设计原理和统计方法,以两市疾病发病率为例,采用Prais-Winsten法和Newey-West法拟合线性回归模型,并对结果进行了详细的解释和比较。在干预实施的时间窗口中存在多个政策转变时,两组ITS可以更好地平衡序列干预前已存在的趋势,科学地估计干预措施有效性具有重要的现实意义,为项目效果评价提供一个新的思路。     

Recent trends in hepatitis A incidence in Brazil

Hepatitis A incidence has been decreasing in Brazil since child vaccination was implemented in 2014. This trend was interrupted by an outbreak among adult male in São Paulo in 2017. This study was outlined to estimate whether the increase of hepatitis A cases among adult men in Brazil was restricted to São Paulo. Cases reported to the national surveillance system from 14 large cities of all Brazilian regions were analyzed. Trends in time series from 2012 to 2018 were estimated by Prais-Winsten regression. The outbreak in São Paulo extended to 2018. In Rio de Janeiro, the number of cases rose again, achieving the same levels reported before the vaccination era. Three of six cities from South and Southeast regions showed an upward trend in the number of cases among adult men (P < .005). The large cities in the other three Brazilian macroregions showed a decrease or stabilization of cases without an increase among male adults. The increase of hepatitis A virus (HAV) cases in Brazil has happened not only in São Paulo, but also in other cities of South and Southeast regions. The northernmost cities were not affected. A change in the epidemiological pattern of HAV infection is emerging in Southern Brazil.     

基于时序心脏模型样本均衡方法的心律失常分类

心律失常自动分类作为计算机在临床上的重要应用,可以有效辅助心血管疾病的诊断,但实验中样本不均衡问题严重影响分类精度。目前用于解决样本不均衡问题的主流方法为对抗神经网络,但存在训练不稳定和模式崩溃等问题,且仅依靠数据进行学习,缺乏一定的生理意义。因此提出基于时序心脏模型的样本均衡方法生成心电数据,在2018年中国生理信号挑战赛提供的12导联数据集上进行实验,采用深度残差网络作为分类模型分别对每个导联进行训练,通过极端梯度提升算法实现导联融合。经过样本均衡后,各类F1分数均有提升,左束支阻滞(LBBB)、ST段降低(STD)、ST段抬升(STE)的改善尤其显著,分别由扩增前的0.706、0.684、0.524提升至0.832、0.809、0.618。为验证本方法的通用性,对PTB数据集进行独立测试,分类准确率达到98.64%。实验结果表明,基于时序心脏模型生成仿真数据能够有效改善实验样本不均衡现象。