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1、1,疾病的分布,Distribution of Disease,What is Distribution of Disease When Where Who,INTRODUCTION,?,3,疾病的分布是指疾病的人群现象,是描述疾病事件（发病、患病、死亡等）Time （时间）Place （空间）Person（人间）在流行病学中简称“三间分布”,4,Example,You have been asked to investigate an event in which 2,220 people were exposed and 1,520 of them died. Your role as a
2、n epidemiologist is to ask questions about person, place and time.,5,How do we ask questions? Surveys -of survivors -of other related persons,Example,6,Objectives,第一节疾病频率测量指标第二节 疾病流行强度第三节 疾病分布形式,Frequency of Disease Measurement Intensity of EpidemicDimension distributionsof disease,7,Directions: Thi
3、s chapter describes the basic measures of disease frequency used in epidemiologic research,Frequency of Disease Measurement,第一节 疾病频率测量指标,8,发病频率测量指标 患病频率测量指标 死亡频率测量指标 预期寿命及相关指标,Morbidity frequency measures Prevalence related measures Mortality frequency measures Life expectancy related measures,9,一、发
4、病指标,发病率（incidence） 罹患率（attack rate） 续发率（secondary attack rate）,10,发病率（incidence）,定义 在一定期间内，一定人群中某病新发生的病例出现的频率。,Definition the rate of new cases of a disease in a specified population over a defined period,发病率= KK=100%,1000/千，或10000/万,一定期间内某人群中某病新病例数,同时期暴露人口数,11,Incidence rate,Numerator New (incident
5、) cases appearing during a time period (usually one year) Denominator Average population during the time period Midpoint population estimateCases per 10X per yearExample: 234 per 100,000 per year,12,罹患率（attack rate）,定义在某一局限范围，短时间内的发病率。观察时间可以日、周、旬、月为单位。,Definitionthe proportion of a population affect
6、ed by the disease during a prescribed, usually short, period of time.,13,Incidence rate and attack rates,An outbreak of hepatitis A in Ajloon from March 1 to march 14 2000 had an attack rate of 25 per 1000 The yearly incidence rate of hepatitis A .in Ajloon is 238 per 100,000 per yearHow do you comp
7、are these rates?,14,Is their an outbreak? Incidence and attack rates compared,1. Adjust population to make rates comparableDivide 238 per 100,000 by 100 2.38 per 1000 per year2. Adjust time period2 weeks = 2/52 year2.38 (2/52) = 0.110.11 per 1000 per 2 weeks 25/1000,15,续发率（secondary attack rate）,定义指
8、在某些传染病最短潜伏期到最长潜伏期之间，易感接触者中发病的人数占所有易感接触者总数的百分率。,Definitionnumber of cases in the outbreak divided by the total number of susceptible population.,续发率100 易感接触者总人数,潜伏期内易感接触者中发病人数,16,Secondary attack rate,NumeratorSecondary cases (among persons defined as contacts) Denominator All contacts at risk (exclu
9、de primary and coprimary cases),17,二、患病指标,患病率（prevalence）感染率（infection rate）残疾率（prevalence of disability）,18,患病率（prevalence）,定义 某特定时间内一定人口中某病新旧病例所占比例。the total number of cases of a specific disease in existence in a given population at a certain time .,时点患病率（point prevalence）按观察时间期间患病率（period preval
10、ence）,19,某一时点一定人口中现患某病新旧病例数时点患病率= K该时点人口数（被观察人数）某观察期间一定人口中现患某病的新旧病例数期间患病率= K 同期的平均人口数（被观察人数）K=100%,1000/千，或10000/万,20,影响因素(Factors ),21,22,Fig1. between the Incidence and prevalence of the relationship,流入,蓄水池,23,24,感染率（infection rate）,定义 某个时间内能检查的整个人口样本中，某病现有感染者人数所占的比例,Definitionpercentage of the po
11、pulation from which a specific infectious pathogen is isolated.,25,残疾率（prevalence of disability）,定义 某一人口中，在一定期间内每百（或千、万、十万）人中实际存在的残疾人数。即是指通过询问调查或健康检查，确诊的病残人数与调查人数之比。残疾率=残疾人数/调查人数K K=100%或1000/千,26,三、死亡指标,死亡率（mortality rate）病死率（case fatality rate）生存率（survival rate）累积率（cumulative rate）,27,死亡率（mortalit
12、y rate）,定义在一定期间内，一定人口中，死于某病（或死于所有原因）的频率。,DefinitionThe number of deaths in the population divided by the average population (or the population at midyear) is the crude death rate.,某期间内（因某病）死亡总数死亡率= K 同期平均人口数K=100%,1000/千，或10000/万,28,Mortality frequency measures,Crude death rate Crude mortality rate
13、Age-specific mortality rate Sex specific mortality rate Race specific mortality rate Cause specific mortality rate Combinations of specific mortality rates,29,病死率（case fatality rate）,定义 病死率是表示一定时期内，患某病的全部病人中因该病死亡者的比例某时期内因某病死亡人数病死率= 100%同期患某病的人数,The proportion of individuals contracting a disease who
14、 die of that disease.,30,生存率（survival rate）,定义 指接受某种治疗的病人或某病患者中，经若干年随访（通常为1、3、 5 年）后，尚存活的病人数所占的比例。随访满n年尚存活的病例数生存率= 100%开始随访的病例数,The five-year survival rate is a term used in medicine for estimating the prognosis of a particular disease.,31,累积率（cumulative rate）,定义 某一年龄以前发生或死于某种疾病的累积概率的大 小。累积率可由各年龄发病或
15、死亡率相加获得。多用%表示累积（死亡或发病）率=（年龄组（死亡或发病）专率年龄距）100%,32,Table 1. Leading Causes of Mortality and Burden of Disease world, 2004,% Ischaemic heart disease 12.2 Cerebrovascular disease 9.7 Lower respiratory infections 7.1 COPD 5.1 Diarrhoeal diseases 3.7 HIV/AIDS 3.5 Tuberculosis 2.5 Trachea, bronchus, lung cancers 2.3 Road traffic accidents 2.2 Prematurity, low birth weight 2.0,
