流行病学课件疾病分布

Department of Epidemiology Public Health College of Harbin Medical University 1 Department of Epidemiology Public Health College of Harbin Medical University What is Distribution of Disease When Where Who pINTRODUCTION Department of Epidemiology Public Health College of Harbin Medical University 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” 3 Department of Epidemiology Public Health College of Harbin Medical University 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 an epidemiologist is to ask questions about person, place and time. 4 Department of Epidemiology Public Health College of Harbin Medical University How do we ask questions? Surveys -of survivors -of other related persons Example 5 Department of Epidemiology Public Health College of Harbin Medical University 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 Epidemic Dimension distributions of disease 6 Department of Epidemiology Public Health College of Harbin Medical University Directions: This 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 7 Department of Epidemiology Public Health College of Harbin Medical University 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 8 Department of Epidemiology Public Health College of Harbin Medical University 一、发病指标 发病率（incidence） 罹患率（attack rate） 续发率（secondary attack rate） 9 Department of Epidemiology Public Health College of Harbin Medical University 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= K K=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 10 Department of Epidemiology Public Health College of Harbin Medical University Incidence rate Numerator New (incident) cases appearing during a time period (usually one year) Denominator Average population during the time period Midpoint population estimate Cases per 10X per year Example: 234 per 100,000 per year 11 Department of Epidemiology Public Health College of Harbin Medical University 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。 Definition the proportion of a population affected by the disease during a prescribed, usually short, period of time. 12 Department of Epidemiology Public Health College of Harbin Medical University Incidence rate and attack rates v 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 year How do you compare these rates? 13 Department of Epidemiology Public Health College of Harbin Medical University Is their an outbreak? Incidence and attack rates compared 1. Adjust population to make rates comparable Divide 238 per 100,000 by 100 2.38 per 1000 per year 2. Adjust time period 2 weeks = 2/52 year 2.38 (2/52) = 0.11 0.11 per 1000 per 2 weeks 南方 Schistosomiasis is limited in some provinces in the south HIV infection in Yunnan Province Nasopharyngeal carcinoma in Guangdong Esophageal cancer in Henan Jiangsu Qidong Liver Cancer Hypertension north South 91 Department of Epidemiology Public Health College of Harbin Medical University Fig18. Chinas cumulative reported HIV infection distribution by province (1985-2001) 92 Department of Epidemiology Public Health College of Harbin Medical University 疾病的城乡分布 The disease city and countryside distribution 城市 City 人口多，密度大 Population is many , density is big 交通拥挤，人口流动性大 Traffic congestion, population mobility 较少经水传播传染病流行 Less water-borne epidemics 虫媒传染病城市Insect intermediary infectious disease City 某些地方病发病率The incidence of certain endemic diseases 呼吸道传染病不易流行Respiratory tract infectious disease not easy popular 疾病的城乡分布 The disease city and countryside distribution 94 Department of Epidemiology Public Health College of Harbin Medical University 疾病的地区聚集性 （endemic clustering） 定义 疾病频率高于周围地区的情况 Disease frequency is higher than the surrounding area 95 Department of Epidemiology Public Health College of Harbin Medical University 地方性疾病（简称地方病） 定义 指局限于某些特定地区内相对稳定并 经常发生的疾病。在我国地方病指与当地水土因 素、生物学因素有密切关系的疾病，其病因存在 于发病地区的水、土壤、粮食中 。 Present in a community at all times but in relatively low frequency. Something that is endemic is typically restricted or peculiar to a locality or region. 96 Department of Epidemiology Public Health College of Harbin Medical University 判断依据 该地区的各类居民、任 何民族的发病率均高 在其他地区居住的相似 的人群中该病的发病频率 均低，甚至不发病。 incidence of the disease in any ethnic may increase in the residents in the area similar residents lived in other areas have the lower incidence, or even not occur the disease criteria of endemic diseases 97 Department of Epidemiology Public Health College of Harbin Medical University criteria of endemic diseases who immigrate the area over a period of time, its incidence approaches that in local population; the people emigrate the area, the incidence would reduce, or symptoms alleviate or self- healing. in addition, the local animals are also susceptible to the same disease 迁入该地区的人经一段时间后 ，其发病率和当地居民一致人 群迁出该地区后，发病率下降 或患病症状减轻或自愈 当地的易感动物也可发生同样 的疾病 判断依据 98 Department of Epidemiology Public Health College of Harbin Medical University p移民流行病学 （migrant epidemiology） 定义 对移民人群的疾病分布进行研究，以探讨 病因。它是通过观察疾病在移民、移民移入国当地 居民及原居地人群间的发病率、死亡率的差异，从 其差异中探讨病因线索，区分遗传因素或环境因素 作用的大小。 99 Department of Epidemiology Public Health College of Harbin Medical University 若环境因素是主要因素 移民原居住地人群 发病率或死亡率 移民移居地当地居民 若遗传因素是主要因素 移民原居住地人群 发病率或死亡率 移民移居地当地居民 100 Department of Epidemiology Public Health College of Harbin Medical University Local residents in Japan, the United States white and third generation, second- generation Japanese immigrants age specific death rate of gastric cancer Fig19 101 Department of Epidemiology Public Health College of Harbin Medical University 分析结果注意 移民移居他地的原因及移民本身的人口学 特征。 如：年龄、职业、文化