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1、医院感染:凡住院病人,陪诊者或医院工作人员由于医护工作而遭受的感染,并有临床表现的微生物性疾病。临床流行病学:是将流行病学原理和方法应用于临床诊断,治疗,预后判断,医事决策及临床医学研究等方面方法学。发病率:一定期间内(一般为一年)特定人群中某病新病例出现的频率。患病率:又称现患率,是指某特定时间内总人口中某病现患病例所占的比例i。患病率=发病率病程。死亡率:在一定期间内(一般为一年)特定人群中总死亡人数与该人群同期平均人口数之比。(注意:死亡于所有原因的死亡率是一种未经过调整的率,分子分母的同一群体)病死率:一定期间内(一般为一年)患某病的全部患者中因该病而死亡的频率。散发:是指某病的发病率
2、呈历年的一般水平,各病例期间的发病时间和地点方面无明显关系,表现为散在发生。确定应参照当地前3年该病的发病率水平而定。暴发:是指在一个局部地区或集中单位中,短时间内突然有很多相同患者出现,这些人多有相同传染源或传播途径。流行:是指一地区发病率明显超过历年散发发病率水平。病因:泛指一切与疾病的发生和发展有关的因素。横断面研究:在一特定时间内,即某一时点或短时间内,通过普查或抽样调查法,对特定人群中有关因素与疾病或健康状况关系进行调查,确定患病率,从而描述这一时间内疾病分布及观察某些因素与疾病间关系。普查:是指在特定的时间内,对某一特定人群中的每个成员进行的调查或检查。抽样调查:从研究对象的总体按
3、一定原则抽取一部分具有代表性的个体i,通过对样本的研究推断总体。偏倚:是指流行病学研究中,由于某种或某组因素的影响使研究结果偏离真实情况的现象。病例对照研究:以现在确定患有某种特定疾病病人为例,不患有疾病但有可比性个体为对照,调查过去对某些可疑因素暴露与否认暴露程度,通过比较暴露差异。估计各种偏倚对研究结果影响后,推断这些因素作为病因可能性。匹配:指在选择研究对象时,通过一些限制条件,使对照和病例在某些特征或混杂因素上保持一致,以提高研究的效率,同时增强对照与病例的可比性。混杂因素:性别,年龄,民族等因素常常既与研究疾病有因果关联,又与某些需研究的暴露因素有关。这些因素的存在常歪曲暴露因素与疾
4、病的关联,从而导致混杂偏倚。匹配过头:将不起混杂作用的因素加以匹配,使研究结果失真,或因匹配因素过多,使未进行匹配的研究因素趋于一致,从而掩盖了该因素的作用。比值比:指某事物发生的概率与不发生的概率之比。队列研究:将某特定人群 分为暴露于某因素与未暴露于某因素或不同暴露水平下亚群,追踪观察,一定时间后,比较各组的发病率或死亡率的差异,从而间掩盖暴露因素与疾病或死亡因果联系是否成立并准确计算联系强度。暴露:是指接触过某种研究因素,具备某特征或处于某状态。累积发病率(CI):观察期内出现新病例的频率。发病密度(ID):观察期出现新病例于人时数之比。(动态)。相对危险度(RR):为暴露组发病率与非暴
5、露组发病率之比。又称危险比或率比。归因危险度(AR):又特异危险度,超额危险度,率差。是暴露组发病率或死亡率与非暴露组发病率或死亡率相差绝对值。归因危险度百分比(ARP或AR%):又称病因分值。指暴露人群中的发病或死亡归因与暴露的部分占该人群全部发病或死亡的百分比。流行病学实验:是以人为研究对象,将其随机地分为实验组和对照组,对实验组给予一定的干预措施随访,观察一段时间后,比较两组人群的结局并分析其差异,从而判断干预措施的效果。类实验:不完全具备离心泵学实验特征。盲法:一方或多方不知道研究对象,分组对象的方法。单盲:只有研究者了解分组情况,研究对象并不知道自己出于实验组还是对照组。双盲:研究者
6、和研究对象都不了解试验分组的情况,有设计者安排和控制全部实验。三盲:研究者,研究对象,研究设计者三方均不了解分组情况,从而避免了偏倚。疾病预后研究:疾病发生后对将来发展为各不同后果(痊愈,复发,恶化,伤残,并发症和死亡)预测或身前评估。筛检:以快速法,从表面健康人群中找可能有病人,筛检不是诊断,筛检阳性要进一步诊断,对确诊者进行干预。灵敏度:(真阳性率):诊断实验能讲实际有病的人正确地判为患者的百分率。=A/A+C100%.特异度(真阴性率):诊断实验能将实际无病的人正确判定为非患者的比例。=D/B+D100%假阴性率(漏诊率):计算实际有病错判为阴性的人占全部患者的比例。=C/A+C100%
7、=1-特异度。假阳性率(误诊率):计算实际实际无病错判为阳性的人占全部患者的比例。=B/B+D100%=1-特异度。约登指数:灵敏度与特异度之和减去1。(越接近1越好)符合率:指实验结果的真阳性和真阴性人数占 受试总人数的比例。=A+D/A+B+C+D100%可靠性:在相同条件下重复试验获得相同结果稳定程度。效益:其评价指标是预测值,分阴性和阳性。阳性预测值:指试验阳性结果中真正不患病的比例。阴性预测值:指试验阴性中真正不患病的比例。并联试验:同时做几项诊断试验,只一项阳性可定阳性。串联试验:依次做几项试验,是否作下一个试验要根据上一个试验结果来决定,在一系列多项试验中,每一次试验均为阳性,最
8、后才判为阳性。Visa-free policy brings Chengdu biz, tourism boost. Making national headlines several times, Chengdus 72-hour visa-free policy has attracted wide attention from both Chinese and foreign experts and businessmen since it took effect on Sept 1 last year. The program permits citizens from 51 coun
9、tries and regions including the United States, Australia, Canada and Japan who have valid visas and flight tickets to a third country to spend three days in the city. The capital of Sichuan province is the first city in the western region of China to offer foreign tourists a three-day visa and the f
10、ourth nationwide to adopt the policy following Shanghai, Beijing and Guangzhou. Li Zhiyong, deputy dean of the tourism institute at Sichuan University, said the move contributes to a large increase in the number of overseas tourists and raises the citys level of internationalization. The policy will
11、 also bring direct economic revenue, Li said. Chengdu has many cultural legacies and is also a paradise for panda lovers with the worlds largest breeding and research center. Three days are long enough for foreign visitors to visit those iconic tourist spots, he noted. The city is home to the remain
12、s of the Jin sha civilization that dates back more than 3,000 years as well as the Qing cheng Mountains and the Du jiang yan irrigation system. Qing cheng has long been recognized as the birthplace of Taoism, Chinas ancient indigenous religion, while Du jiang yan is considered to be the oldest funct
13、ioning water-control project in the world. Chengdu ranked third in tourist facilities, management and services among 60 Chinese cities in a customer satisfaction survey released last year. But, Li added that efforts are still needed to develop more tourism products, improve English services and prov
14、ide accurate translation of traffic signs and scenic billboards. Zhao Yun, chairwoman of British Chamber of Commerce Southwest China, told China Daily that his colleagues found the policy very convenient. A British client once flew here and stayed for just one day to check her ordered goods, she sai
15、d. Zhao was born in Shanxi province, but she has lived in Chengdu for more than 10 years. My life was like a running race moving from place to place. I also lived in Beijing and Shanghai before, she said. But Chengdu is a place that you never want to leave once settling down. It is now my second hom
16、etown, she said. If the environment is further improved, the city will attract more people to visit and live, with the 72-hour visa-free policy and compelling conditions in transportation, culture, climate and cuisine, he said. Foreigners also gave positive feedback on the policy. A spokesman from D
17、ell Inc said the company has a global hub of operation in Chengdu, so the three-day visa has an immediate and positive influence on the companys business development. Rudy Buttignol, president of the public broadcasting company in British Columbia, Canada, said his work requires frequent travel to C
18、hengdu and the policy makes the trips easier. Data from the citys public security bureau shows some 100 foreign visitors enjoyed the 72-hour policy by the end of March, most of them from the United States, the United Kingdom and Germany. Chengdu also reported robust growth in its overall tourist ind
19、ustry last year. Official statistics show that it received some 150 million tourists last year, an increase of 28 percent from 2012. Around 1.7 million came from abroad, an increase of 12 percent. Total revenue from tourism surpassed 133 billion yuan ($21.7billion). During his visit to Kazakhstan in
20、 September, Chinese President Xi Jinping proposed that China and Central Asia join hands to build a Silk Road economic belt to boost cooperation. The idea has been widely echoed in Central Asian countries, becoming an encouraging blueprint for Chinese areas along the Silk Road that has linked Asia a
21、nd Europe for more than 2,000 years. In the next three weeks, China Daily reporters will travel through the belt in China and in Kazakhstan, Uzbekistan and Turkey. They will show the progress and expectations of the countries, businesses and peoples on the route. Shaanxi - the start of the ancient S
22、ilk Road - has positioned itself as the new starting point for the development of the Silk Road Economic Belt, which will strengthen Chinas cooperation with Central Asian countries, a senior official said. Shaanxi Governor Lou Qinjian said the province is fresh, rich and unique, as it was when it an
23、chored one end of the ancient Silk Road. It is the best option for accommodating industrial transfers from East China or the world at large, he said on Wednesday in Xian.Lou held a joint interview with 27 media, including China Daily, the first in a series of interviews entitled Chinese Media Along
24、the Silk Road. The interviews will be in Shaanxi and Gansu provinces and the Xinjiang Uygur autonomous region, as well as Kazakhstan, Uzbekistan and Turkey. The media group held the first interview on Wednesday morning in Xian, the starting point of the ancient Silk Road, a trade channel established more than 2,000 years ago linking China, Central Asia and Europe.