Meta—analysis及其在流行病学中的应用

Ｍｅｔ－ａｎａｌｙｓｉｓ是对先前研究资料进行合并分析的一种新的研究方法，其原理简单、系统，结果全面、量化，可靠性好，为流行病学研究提供了一种强有力的统计分析手段，本文介绍了这种方法的基本原理，讨论讨论了在流行病学应用中的一些问题，试用于极低频电磁与儿童白血病关系的研究，结果表明儿童白血的发生与极低频电磁场暴露有关。     

极低频电磁场与儿童白血病的关系Meta－analysis研究

本文应用Ｍｅｔａ－ａｎａｌｙｓｉｓ等方法，对国内外关于极低频电磁场与儿童白血病关系的九个研究资料进行统计合并与综合分析，结果表明，九个研究的结果具有一致性，极低频电磁场是儿童白血病的危险性因素，ＯＲ＝１．６３７２，９５％Ｃ．Ｉ＝１．２９７７～２．０６５６Ｐ＜０．０１。合并人群归因危险度为７．７５％。     

极低频电磁场与儿童白血病关系的Meta分析

目的 探讨极低频电磁场与儿童白血病的关联程度.方法 采用Meta分析的方法,对国内外公开发表的8篇关于极低频电磁场与儿童白血病的流行病学研究文献进行综合定量再分析.根据资料一致性检验采用固定效应模型计算总OR值.结果 极低频电磁场与儿童白血病之间总OR值为1.58,95%可信区间（95%CI）为1.24～2.03,差异有统计学意义（χ^2=13.11,P＜0.01）.结论 极低频电磁场与儿童白血病具有高度联系,是儿童白血病的危险因素之一.     

电磁场与肿瘤的关系及其可能的机制

电磁场与肿瘤的关系及其可能的机制有关儿童白血病与居室中暴露于电力线电磁场的流行病学调查显示，儿童患白血病的危险性略有升高，也有报导在与电相关的职业中白血病和脑肿瘤的发病者较多。由于接触评定技术的提高，最近的一些研究为阐明肿瘤与电磁场之间的关系提供了较...     

极低频电磁场与癌症

随着现代电子工业技术的飞跃发展，电磁能在军事、科研、工农业生产、通讯等行业已广泛应用，现已进入了家庭生活。接触电磁场的人数和空间电磁场强度已逐渐增加，电磁场污染及其对人体健康的潜在危害，已引起各国学者的普遍关注。自1979年hertheimer和Leener的研究提示高压线与儿童白血病之间具有相关性’‘’以来，众多流行病学研究已将重点集中于极低频（EX－tremelyLowFreauency，ELF）电磁场与癌症之间的关系上，然而生物学研究尚未证实两者之间的因果关系“”’。ELF电磁场频率为0～300HZ。高压线、视屏显示终端（VDT）和家用…     

极低频电磁场对人体健康效应的流行病学研究进展

极低频电磁场对人体健康的效应自20世纪70年代以来受到了广泛的关注,在肿瘤,尤其是儿童白血病以及神经行为、神经退行性疾病、心血管疾病、生殖功能、子代发育、免疫学和血液学等方面进行了大量的流行病学研究,本研究对上述研究结果进行综述。     

家庭电磁场有引起儿童白血病的危险

家用电器产生的电磁场特别是 50或 6 0Hz的电磁场对儿童可能有致癌作用 ,这是世界卫生组织下属的国际肿瘤研究中心(IARC)对过去 2 0年来的多起研究得出的结论。经常暴露在这种电磁场环境的儿童比一般儿童患白血病的危险性增加 1倍多。但电磁场与儿童和成人的其他恶性肿瘤的联系没有显著性 ,也没有证据表明居住在高压电线附近的儿童容易患白血病。关于电磁场与白血病之间的联系最早见于 1 979年 ,IARC科学工作小组搜集了自那时以来的数百份有关实验室与动物试验报告得出了上述结论。负责这个项目工作的Baan博士说 ,这并不能证明低剂量水…     

遗传与环境因素与儿童白血病的Meta分析

目的 运用Meta分析方法综合分析评价儿童白血病的遗传与环境因素.方法 收集国内有关儿童白血病遗传与环境因素的病例对照研究文献20篇,采用可信区间方差分析法计算各相关因素的ORc及95％ CI.结果 服用鱼肝油是儿童白血病的保护因素,接触农药、X线暴露、极低频电磁场暴露、住宅附近三废污染、室内装修、室内氡污染、2年内擂冒史、服用氯霉素和家族肿瘤遗传史是儿童白血病的危险因素.结论 农药、X线、极低频电磁场、三废污染、室内装修室内氡污染、2年内感冒史、服用氯霉素和家族肿瘤遗传史较易致儿童白血病,应尽量避免接触.     

环境苯暴露与儿童白血病

慢性苯暴露对血液系统的毒性作用已引直普遍关注。流行病学资料显示环境中的苯是引起儿童白血病发病率日益上升的重要因素之一，本从流行病学研究，儿童的个体易感性与苯代谢有关的酶的多态性等方面对环境苯致儿童白血病的作用进行综述。     

工频电磁场暴露对细胞遗传毒性的研究进展

工频电磁场（power frequency electromagnetic field）是由输电线及家用电器所产生的一种极低频电磁场。我国和欧洲一些国家采用50Hz为工作频率，而西方一些国家（如美国、加拿大）使用60Hz。电磁场暴露与癌症的关系至今尚无定论。流行病学调查显示，工频电磁场暴露可导致儿童白血病发病率升高，据此，国际癌症研究机构（IARC）已于2001年将其列为“可疑致癌物质”。     

HLA-II类基因与妊娠期糖尿病相关性的研究

有关HLAII类基因的研究已经涉及到遗传学、免疫学、临床医学。其中HLAII与自身免疫性疾病的相关性是非常重要且引人注目的问题,特别是HLAII类基因与糖尿病相关性研究已取得了一定的结论,HLAII类基因与病理性妊娠的相关研究也有所进展。妊娠期糖尿病的病因及发病机理目前尚不清楚。妊娠期糖尿病为糖尿病的一独立特殊型,它与HLAII类基因相关性的研究已开始起步,不同的HLAII类基因可能控制妊娠期糖尿病的抑制性和易感性。     

The impact of managers' perceptions of learning organizations on innovation in healthcare: sample of Turkey

Organizational learning is the process of increasing effective organizational activities through knowledge and understanding. Innovation is the creation of any product, service or process, which is new to a business unit. Significant amount of research on organizational learning place a central meaning on the fact that there is a positive relationship between organizational learning and innovation. Both organizational learning and innovation are essential for organizations to prepare for change. The aim of this study is to determine to what extent the identified learning organization dimensions are associated with innovation. The study used a quantitative non‐experimental design employing statistical analysis via multiple regression and correlation methods to identify the relationships between the variables examined. Because the research was conducted in a non‐experimental way, learning organization dimensions are referred to as predictor variables, and innovation is referred to as the criterion variable. Watkins and Marsick's Dimensions of the Learning Organization Questionnaire was used in the study. Questionnaires were distributed to 498 hospital managers and, 243 valid responses were used in this study. Therefore, 243 hospital managers working at 250 Ministry of Health (public) hospitals across Turkey participated in the study. Results demonstrate that there are significant and positive correlations between learning organization dimensions and innovation. Intercorrelations between learning organization dimensions and correlations between learning organization dimensions and innovation were average and high, respectively. Results further indicate that the dimensions of the learning organizations explained 66.5% of the variance for the innovation. Copyright © 2012 John Wiley & Sons, Ltd.     

EpiHealth: a large population-based cohort study for investigation of gene–lifestyle interactions in the pathogenesis of common diseases

The most common diseases affecting middle-aged and elderly subjects in industrialized countries are multigenetic and lifestyle related. Several attempts have been made to study interactions between genes and lifestyle factors, but most such studies lack the power to examine interactions between several genes and several lifestyle components. The primary objective of the EpiHealth cohort study is to provide a resource to study interactions between several genotypes and lifestyle factors in a large cohort (the aim is 300,000 individuals) derived from the Swedish population in the age range of 45–75 years regarding development of common degenerative disorders, such as cardiovascular diseases, cancer, dementia, joint pain, obstructive lung disease, depression, and osteoporotic fractures. The study consists of three parts. First, a collection of data on lifestyle factors by self-assessment using an internet-based questionnaire. Second, a visit to a test center where blood samples are collected and physiological parameters recorded. Third, the sample is followed for occurrence of outcomes using nationwide medical registers. This overview presents the study design and some baseline characteristics from the first year of data collection in the EpiHealth study.     

Study control,violators, inclusion criteria and defining explanatory and pragmatic trials

Important differences between explanatory and pragmatic studies were originally argued by Schwartz and Lellouch. Three important differences between the two types of study involve study control, study violators and inclusion criteria. It was originally argued that explanatory studies are highly controlled, and pragmatic studies may be looser and more like 'real life'. It was argued that an explanatory study should only analyse those receiving treatment, and a pragmatic study would analyse all randomized patients. Explanatory trials are said to use homogeneous groups, and pragmatic studies have less selection (better generalizability). Some suggestions are put forward to update the original distinctions between these two attitudes for future study design. Poor study control is undesirable (but might be necessary) and should not be welcomed as pragmatic. The intention-to-treat strategy is now considered as standard for nearly all trials. Homogeneity is a red herring for studies in humans. Inclusion criteria should be minimized and they should not be used to justify claims of representativeness. Routine criticism of randomized controlled trials for being unrepresentative is unwarranted. We should accept that most trials in humans are 'explanatory'. The division line should be moved, so that pragmatic studies are in the domain of non-therapeutics and complex treatments.     

Linkage of the US National Health Interview Survey to air monitoring data: an evaluation of different strategies

The goal of this study is to describe linkages between the National Health Interview Survey (NHIS) and Environmental Protection Agency (EPA) air monitoring data, specifically how the linkage method affects characteristics and exposure estimates of study samples and estimated associations between exposure and health. In the USA, nationally representative health data are collected in the NHIS and annual air quality data are collected by the EPA. The linkage of these data for research is not straightforward and the choices made may introduce bias into results. The 2000-2003 NHIS and air quality data for six air pollutants were linked by residential block group and monitor location, which differ by pollutants. For each pollutant, three annual exposure variables were assigned to respondents: (1) average of all monitors in the county, (2) of monitors within a 5-mile radius of the distance between block group and monitor, and (3) within a 20-mile radius. Exposure estimates, study sample characteristics, and association between fine particle exposure and respondent-reported health status were compared for different geographic linkage methods. The results showed that study sample characteristics varied by geographic linkage method and pollutant linked. Generally, the fewer the NHIS respondents linked, the higher is the pollution exposure and lower is the percentage of non-Hispanic whites. After adjustment for sociodemographic and geographic factors, associations between fine particles and health status were generally comparable across study samples. Because exposure information is not available for all potential participants in an epidemiological study, selection effects should be considered when drawing inferences about air quality-health associations. With the current monitoring data system, the study sample is substantially reduced when linkage to multiple pollutants is performed.     

A survey of relationship between rheumatoid arthritis and hearing disorders

RA (rheumatoid arthritis) is a chronic multisystem disease with a variety of systemic manifestations. One of these manifestations, is hearing disorder, so study of the relation between RA and hearing disorders is seem important. This was a case-control study which has done from December 2004 to August 2006. This study compared 50 patients with RA, with age, sex and job-matched as control. Audiometric tests in different frequencies show that hearing threshold in high frequencies specially in 8000 Hz had a significant difference between two groups, also acoustic reflexes were absent in case groups and had significant difference between two groups too. The evaluation of sensory neural hearing loss showed that this hearing loss is sensory not neural. Based on this study, frequent evaluation of audiometric tests is recommended for controlling hearing disorders by therapeutic and rehabilitation procedures in RA patients.     

Is the quality of hospital care a function of leadership?

Multiple regression analysis was used to evaluate the relationship between hospital quality and independent variables of interest. While past studies have analyzed hospital efficiency to evaluate organizational performance, this study is unique because it evaluates the relationship between quality and efficiency. The study incorporates an independent variable, "efficiency," calculated using a variable returns-to-scale, input-oriented, data envelopment analysis methodology. This article provides an innovative approach to measuring cost and quality as the federal government attempts to realign scarce health care resources to better meet local community needs. Data for 143 hospitals in 2000 were analyzed using multiple regression and data envelopment analysis to evaluate hospital quality. These results have managerial implications related to improving hospital quality as well as enhancing organizational performance. The study has policy implications on the relationship between quality and efficiency and supports current initiatives related to pay-for-performance in the health care industry. This study clearly documents the positive relationship between quality and efficiency, which supports the premise that hospital leadership through the effective allocation of resources and development of high-performance work processes is important to improve quality of care.     

The effect of alcoholic beverage excise tax on alcohol-attributable injury mortalities

This study examines the effect of state excise taxes on different types of alcoholic beverages (spirits, wine, and beer) on alcohol-attributable injury mortalities—deaths caused by motor vehicle accidents, suicides, homicides, and falls—in the United States between 1995 and 2004, using state-level panel data. There is evidence that injury deaths attributable to alcohol respond differently to changes in state excise taxes on alcohol-specific beverages. This study examines the direct relationship between injury deaths and excise taxes without testing the degree of the association between excise taxes and alcohol consumption. The study finds that beer taxes are negatively related to motor vehicle accident mortality, while wine taxes are negatively associated with suicides and falls. The positive coefficient of the spirit taxes on falls implies a substitution effect between spirits and wine, suggesting that an increase in spirit tax will cause spirit buyers to purchase more wine. This study finds no evidence of a relationship between homicides and state excise taxes on alcohol. Thus, the study concludes that injury deaths attributable to alcohol respond differently to the excise taxes on different types of alcoholic beverages.