Department of Epidemiology Public Health College of Harbin Medical University 1 哈尔滨医科大学流行病学教研室 Department of epidemiology ， Harbin Medical University

Department of Epidemiology Public Health College of Harbin Medical University What is Distribution of Disease ☆ When ☆ Where ☆ Who INTRODUCTION

Department of Epidemiology Public Health College of Harbin Medical University 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 ”

Department of Epidemiology Public Health College of Harbin Medical University 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 an epidemiologist is to ask questions about person, place and time.

Department of Epidemiology Public Health College of Harbin Medical University 5  How do we ask questions? Surveys -of survivors --of other related persons Example

Department of Epidemiology Public Health College of Harbin Medical University 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 Epidemic  Dimension distributions of disease

Department of Epidemiology Public Health College of Harbin Medical University 7 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

Department of Epidemiology Public Health College of Harbin Medical University 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

Department of Epidemiology Public Health College of Harbin Medical University 9 一、发病指标  发病率（ incidence ）  罹患率（ attack rate ）  续发率（ secondary attack rate ）

Department of Epidemiology Public Health College of Harbin Medical University 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 = —————————————————×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

Department of Epidemiology Public Health College of Harbin Medical University 11 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 10 X per year Example: 234 per 100,000 per year

Department of Epidemiology Public Health College of Harbin Medical University 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。 Definition the proportion of a population affected by the disease during a prescribed, usually short, period of time.

Department of Epidemiology Public Health College of Harbin Medical University 13 Incidence rate and attack rates  An outbreak of hepatitis A in Ajloon from March 1 to march 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?

Department of Epidemiology Public Health College of Harbin Medical University 14 Is their an outbreak? Incidence and attack rates compared 1. Adjust population to make rates comparable Divide 238 per 100,000 by per 1000 per year 2. Adjust time period 2 weeks = 2/52 year 2.38 (2/52) = per 1000 per 2 weeks << 25/1000

Department of Epidemiology Public Health College of Harbin Medical University 15 续发率（ secondary attack rate ） 定义 指在某些传染病最短 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。 Definition number 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

Department of Epidemiology Public Health College of Harbin Medical University 16 Secondary attack rate  Numerator Secondary cases (among persons defined as contacts)  Denominator All contacts at risk (exclude primary and coprimary cases)

Department of Epidemiology Public Health College of Harbin Medical University 17 二、患病指标 患病率（ prevalence ） 感染率（ infection rate ） 残疾率（ prevalence of disability ）

Department of Epidemiology Public Health College of Harbin Medical University 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 prevalence ）

Department of Epidemiology Public Health College of Harbin Medical University 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

Department of Epidemiology Public Health College of Harbin Medical University 20 影响因素 ( Factors ) 患病率升高的因素 病程延长 Course of disease prolongs 发病率升高 Incidence rises 病例迁入 Case immigrate 健康者迁出 Healthy emigrate 诊断水平提高 Raise the level diagnosis 报告率提高 Report rates rise 未治愈者寿命延长 Have not cured person life- span extension 易感者迁入 Susceptible immigrate

Department of Epidemiology Public Health College of Harbin Medical University 21 患病率降低的因素 病程缩短 Shorten the course of the disease 发病率下降 Incidence rate has dropped 病例迁出 Case emigrate 健康者迁入 Healthy immigrate 治愈率提高 Improve the cure rate 病死率提高 Increased case fatality rate

Department of Epidemiology Public Health College of Harbin Medical University 22 Fig1. between the Incidence and prevalence of the relationship 流入 蓄水池

Department of Epidemiology Public Health College of Harbin Medical University 23

Department of Epidemiology Public Health College of Harbin Medical University 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 Definition percentage of the population from which a specific infectious pathogen is isolated.

Department of Epidemiology Public Health College of Harbin Medical University 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

Department of Epidemiology Public Health College of Harbin Medical University 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 ）

Department of Epidemiology Public Health College of Harbin Medical University 27 死亡率（ mortality 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。 Definition The 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

Department of Epidemiology Public Health College of Harbin Medical University 28 Mortality frequency measures  Crude death rate  Crude mortality rate  Age-specific mortality rate  Sex specific mortality rate  Race specific mortality rate  Cause specific mortality rate  Combinations of specific mortality rates

Department of Epidemiology Public Health College of Harbin Medical University 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 die of that disease.

Department of Epidemiology Public Health College of Harbin Medical University 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.

Department of Epidemiology Public Health College of Harbin Medical University 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%

Department of Epidemiology Public Health College of Harbin Medical University 32 Table 1. Leading Causes of Mortality and Burden of Disease world, 2004 % 1. Ischaemic heart disease Cerebrovascular disease Lower respiratory infections COPD Diarrhoeal diseases HIV/AIDS Tuberculosis Trachea, bronchus, lung cancers Road traffic accidents Prematurity, low birth weight 2.0 Mortality

Department of Epidemiology Public Health College of Harbin Medical University 33 % 1. Lower respiratory infections Diarrhoeal diseases Depression Ischaemic heart disease HIV/AIDS Cerebrovascular disease Prematurity, low birth weight Birth asphyxia, birth trauma Road traffic accidents Neonatal infections and other 2.7 DALYs Table 1. Leading Causes of Mortality and Burden of Disease world, 2004

Department of Epidemiology Public Health College of Harbin Medical University 34 (2003 年中国卫生统计提要 ) Table2.

Department of Epidemiology Public Health College of Harbin Medical University 35 (2003 年中国卫生统计提要 ) Table3.

Department of Epidemiology Public Health College of Harbin Medical University 36 (2003 年中国卫生统计提要 ) Table4.

Department of Epidemiology Public Health College of Harbin Medical University 37 四、预期寿命指标 预期寿命（ life expectancy ） 潜在减寿年数（ PYLL ） 伤残调整寿命年（ DALY ）

Department of Epidemiology Public Health College of Harbin Medical University 38  预期寿命（ average life expectancy ） 定义 X 岁时的平均预期寿命表示 x 岁尚存活 者预期尚能存活的年数

Department of Epidemiology Public Health College of Harbin Medical University 39  潜在减寿年数 ( potential years of life lost, PYLL ) 定义 指某年龄组人口因某病死亡者的预期寿命 与实际死亡年龄之差的总和，即死亡所造成的 寿命损失。。    e i ii da PYLL 1 年龄组年龄组 预期 寿命 某年龄组 的死亡人 数 剩余年龄 ai= e-(i+0.5)

Department of Epidemiology Public Health College of Harbin Medical University 40  伤残调整寿命年 定义 指从发病到死亡所损失的全部健康寿命年 寿命损失年 (YLL) 因早死所致 包括 健康寿命损失年 (YLD) 疾病所致残疾引起 （ disability adjusted life year, DALY ）

Department of Epidemiology Public Health College of Harbin Medical University 41 某人群 暴露人群 某病患者 发病率 ( 罹患率 ) 新发 因某病死亡者 病死率 康复率 因所有原因死亡者 死亡粗率 死亡专率 ( 某病死亡率 ) 某一时期内 小结

Department of Epidemiology Public Health College of Harbin Medical University 42 第二节疾病流行强度 散发（ sporadic ） 暴发（ outbreak ） 流行（ epidemic ） Intensity of Epidemic

Department of Epidemiology Public Health College of Harbin Medical University 43 一、散发（ sporadic ） 定义 指发病率呈历年的一般水平，各病例间在发 病时间和地点方面无明显联系，散在发生。 Occurring irregularly, usually infrequently ， occurring at random or by chance.

Department of Epidemiology Public Health College of Harbin Medical University 44 乙脑病毒

Department of Epidemiology Public Health College of Harbin Medical University 45 二、暴发（ outbreak ） 定义 指在一个局部地区或集体单位中，短时间内 突然有很多相同的病人出现。 in epidemiology, the occurrence of infection with a particular disease in a small, localized group, such as the population of a village.

Department of Epidemiology Public Health College of Harbin Medical University 46 三、流行（ epidemic ） 定义 指某病在某地区显著超过该病历年发病率水平。其 发病率水平超过该地一定历史条件下的流行水平时，称大 流行。 The occurrence of more cases of a disease than would be expected in a community or region during a given time period. An epidemic (a sudden outbreak) that becomes very widespread and affects a whole region, a continent, or the world (pandemics).

Department of Epidemiology Public Health College of Harbin Medical University 47 第三节 疾病分布的形式  人群分布  时间分布  地区分布  疾病的人群、地区、时间 分布的综合描述 Dimension distributions of disease  Population Distribution  Time Distribution  Regional Distribution  Disease populations, regions, time distribution of a comprehensive description

Department of Epidemiology Public Health College of Harbin Medical University 48 年 龄 性 别 职 业 种族 宗 教 婚姻与家庭 流动人口 Age gender Occupation ethnicity Religion Marriage and Family Floating Population 一、人群分布 Population Distribution

Department of Epidemiology Public Health College of Harbin Medical University 49 年龄（ Age ）  年龄与疾病之间的关联 比其他因素的作用都强  随着年龄的增长，几乎 大部分疾病的发生频率 都显著变化  Correlation between age and disease, the role than other factors are stronger.  Increase with age, almost the majority of diseases are a significant change in the frequency.

Department of Epidemiology Public Health College of Harbin Medical University 50 Fig2.Distribution of age at death and numbers of deaths, world, 2004

Department of Epidemiology Public Health College of Harbin Medical University 51 Fig3.Four groups of different populations age distribution of female breast cancer characteristics

Department of Epidemiology Public Health College of Harbin Medical University 52 年龄（ Age ） 分析方法  横断面分析 (cross sectional analysis)  出生队列分析 (birth cohort analysis)

Department of Epidemiology Public Health College of Harbin Medical University 53 横断面分析 1880 ～ 1930 各年代同一年龄段的死亡率均呈下 降趋势，至 1930 年的各年龄组死亡率比任何年份 均低（ Fig4 ）。 死亡率峰值年龄可见，第一个死亡率高峰均在 1 ～ 4 岁，很快降至 5 ～ 9 岁的最低点，青少年时开 始上升至第二个高峰。但不同年代第二个高峰年 龄逐渐后移， 1880 年高峰在 20 ～ 29 岁， 1910 年 在 30 ～ 39 岁， 1930 年在 50 ～ 59 岁年龄组。

Department of Epidemiology Public Health College of Harbin Medical University 54 Massachusetts 州男性 1880 、 1910 、 1930 年结核年龄别死亡率 Fig4 Massachusetts State men 1880,1910,1930 year age-specific mortality in TB

Department of Epidemiology Public Health College of Harbin Medical University 55 出生队列分析 各队列间同一年龄的死亡率迅速下降，但患结核而死亡 者的年龄分布型相同，死亡高峰年龄没有改变，均为 0 ～ 4 岁和 20 ～ 29 岁（ Fig5 ）。 1930 年 50 ～ 60 岁组死亡率高峰是由于成年人结核病死 亡（及患病）可能是生命早期感染的再活化，而不是新 感染或再感染所致 。

Department of Epidemiology Public Health College of Harbin Medical University 56 Massachusetts State queue TB males born in age-specific mortality rates Fig5. 出生队列分析

Department of Epidemiology Public Health College of Harbin Medical University 57 横断面分析的结果是个表面的假象 1930 年时的 50 ～ 60 岁者在他们的生命早期 1880 年 0 ～ 9 岁时死 亡率就高于 1890 年及之后各年代的同龄人（如表 5 的 0 ～ 4 一行 的数据所示）。 这一出生队列在 1890 年 10 ～ 19 岁时， 1900 及以后各个年代直 至 1930 年 50 ～ 59 岁，死亡率均较高（表 5 划线的数据）。 因此从横断面分析得出的 1880 ～ 1930 年各年代死亡高峰年龄后 移的现象，实质是 1880 年 0 ～ 9 岁高死亡队列随着年龄的增长均 表现出高死亡率的结果。

Department of Epidemiology Public Health College of Harbin Medical University 58 Table5. Massachusetts State men's age-specific TB death rate (1 / 10 million) Age Year ～40～ ～95～ ～ ～ ～ ～ ～ ～ ～

Department of Epidemiology Public Health College of Harbin Medical University 59 性 别（ gender ）  疾病的死亡率存在明显性 别差异  各年龄别死亡率男性均高 于女性  不同地区或不同疾病有所 不同  男女发病率存在明显差别  significant gender differences in mortality rates of disease  The age-specific mortality rates of men were higher than women  Different regions or different diseases were different  The incidence of significant differences between men and women

Department of Epidemiology Public Health College of Harbin Medical University 60 Fig6. Distribution of deaths by leading cause groups, males and females, world, 2004

Department of Epidemiology Public Health College of Harbin Medical University 61 Fig7.China's mortality rate for men and women of different age groups in 2003

Department of Epidemiology Public Health College of Harbin Medical University 62 Fig8. China's cumulative reported HIV infections by sex distribution 1985 －

Department of Epidemiology Public Health College of Harbin Medical University 63 职 业（ Occupation ） 不同的物理因素、 化学因素、生物 因素及职业精神 紧张，均可导致 疾病分布不同 Different physical factors, chemical factors, biological factors and occupational mental stress, may also lead to the distribution of diseases in different

Department of Epidemiology Public Health College of Harbin Medical University 64

Department of Epidemiology Public Health College of Harbin Medical University 65 Fig9.Percent distribution of the reported symptomatic HIV cases by occupation

Department of Epidemiology Public Health College of Harbin Medical University 66 种族 (ethnicity)  遗传因素  风俗、生活和饮食习惯  社会经济状况、医疗保健 水平  定居点的自然环境和社会 环境  Genetic predisposition  Customs, lifestyle and diet  Socio-economic status, level of health care  Settlements, natural and social environment

Department of Epidemiology Public Health College of Harbin Medical University 67

Department of Epidemiology Public Health College of Harbin Medical University 68 Fig10. United States of different racial / ethnic incidence of hepatitis B

Department of Epidemiology Public Health College of Harbin Medical University 69 Fig11. The United States of different races the incidence of malignant tumors of different Gender

Department of Epidemiology Public Health College of Harbin Medical University 70 宗教 (Religion) 不同宗教有其各自独立的 教义、教规对其生活方式 也产生影响，也对疾病的 发生和分布规律产生影响。 Different religions have their own separate doctrine, canon also had an impact on their lifestyles, but also of disease occurrence and distribution of impact

Department of Epidemiology Public Health College of Harbin Medical University 71

Department of Epidemiology Public Health College of Harbin Medical University 72 婚姻与家庭 (Marriage and Family)  健康  对女性健康的影响  近亲婚配  家庭聚集性  health effects  The impact on women's health  Next of kin marriage  Family aggregation

Department of Epidemiology Public Health College of Harbin Medical University 73

Department of Epidemiology Public Health College of Harbin Medical University 74 流动人口（ Floating Population)  传染病暴发流行的高危人 群  疫区与非疫区间传染病传 播纽带  对传播性传播疾病起不可 忽视作用  给儿童计划免疫的落实增 加难度  Outbreak of infectious diseases in high risk populations  Epidemic and non-epidemic link between the spread of infectious diseases  Effect on the spread of sexually transmitted diseases, the role can not be ignored  The implementation of planned immunization for children more difficult

Department of Epidemiology Public Health College of Harbin Medical University 75

Department of Epidemiology Public Health College of Harbin Medical University 76 二、时间分布  短期波动（ rapid fluctuation ）  季节性 ( seasonal variation )  周期性 （ cyclic change ）  长期趋势（ secular trend ） Time Distribution

Department of Epidemiology Public Health College of Harbin Medical University 77  短期波动（ rapid fluctuation ） 暴 发 Small crowd 区别 短期波动 A larger number of populations

Department of Epidemiology Public Health College of Harbin Medical University 78  季节性 ( seasonal variation ) 定义 指疾病每年在一定季节内呈现发 病率升高的现象. The disease in a certain season each year showing the increased

Department of Epidemiology Public Health College of Harbin Medical University 79 Fig12.

Department of Epidemiology Public Health College of Harbin Medical University 80 Fig13.Incidence of myocardial infarction in Beijing the number of monthly distribution

Department of Epidemiology Public Health College of Harbin Medical University 81  周期性 （ cyclic change ） 定义 指疾病发生频率经过一个相当规律的时 间间隔，呈现规律性变动的状况。通常每隔 1 、 2 年或几年后发生一次流行。 Effective preventive measures can change the laws of the cyclical nature of the disease.

Department of Epidemiology Public Health College of Harbin Medical University 82 Fig14. Baoding the incidence of epidemic cerebrospinal meningitis

Department of Epidemiology Public Health College of Harbin Medical University 83  长期趋势（ secular trend ） 定义 对疾病动态的连续数年乃至数十年的观察， 在这个长时间内观察探讨疾病的病原体、临床表 现、发病率、死亡率等的变化或它们同时发生的 变化情况。 Dynamics of disease for several years or even decades of observation, in this a long time to observe the pathogen of the disease, clinical manifestations, incidence, mortality and other changes or changes in their simultaneous

Department of Epidemiology Public Health College of Harbin Medical University 84 Fig15. United States secular trend in several diseases ( )

Department of Epidemiology Public Health College of Harbin Medical University 85 Fig16. The United States tobacco consumption, changes in male and female lung cancer mortality trends The United States per capita tobacco consumption, changes in male and female lung cancer mortality trends in

Department of Epidemiology Public Health College of Harbin Medical University 86  疾病在不同国家及同一国 家不同地区的分布  疾病的城乡分布  疾病的地区聚集性  地方性疾病  Of the disease in different countries and different regions of the distribution of the same country  Rural-urban distribution of the disease  Regional clustering of the disease  Endemic disease 三、地区分布 Regional Distribution

Department of Epidemiology Public Health College of Harbin Medical University 87

Department of Epidemiology Public Health College of Harbin Medical University 88

Department of Epidemiology Public Health College of Harbin Medical University 89

Department of Epidemiology Public Health College of Harbin Medical University 90 Fig17. Adult mortality rates by major cause group and region, 2004

Department of Epidemiology Public Health College of Harbin Medical University 91 疾病在同一国家内的不同地区分布  血吸虫病 仅限于南方一些省份  HIV 感染者 云南  鼻咽癌 广东 ，故有 “ 广东瘤 ” 之 称  食管癌 河南林县  肝癌 江苏启东  原发性高血压 北方 > 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

Department of Epidemiology Public Health College of Harbin Medical University 92 Fig18. China's cumulative reported HIV infection distribution by province ( )

Department of Epidemiology Public Health College of Harbin Medical University 93  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 < 农村 Insect intermediary infectious disease < Countryside 慢性病及肿瘤发病率 Chronic Diseases and Cancer incidence 出现职业性损害 Occupational injury occurs

Department of Epidemiology Public Health College of Harbin Medical University 94 农村 Countryside 人口密度低 Low population density 交通不便，与外界交往少 Inconvenient transportation, fewer contacts with the outside world 肠道传染病易流行 Intestinal infectious diseases and epidemic-prone 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

Department of Epidemiology Public Health College of Harbin Medical University 95  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

Department of Epidemiology Public Health College of Harbin Medical University 96  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.

Department of Epidemiology Public Health College of Harbin Medical University 97 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

Department of Epidemiology Public Health College of Harbin Medical University 98 Judgment Basis  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

Department of Epidemiology Public Health College of Harbin Medical University 99 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。

Department of Epidemiology Public Health College of Harbin Medical University 100 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

Department of Epidemiology Public Health College of Harbin Medical University 101 Local residents in Japan, the United States white and third generation, second- generation Japanese immigrants age specific death rate of gastric cancer Fig19

Department of Epidemiology Public Health College of Harbin Medical University 102 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、文化水平、社会经济状况、 种族和其他人口学因素及其工作条件、生活环 境的变化是否和非移民相同。

Department of Epidemiology Public Health College of Harbin Medical University 103 表 6. 日本人在美国的日本移民及美国白人一些疾病 的标化死亡率比（ ） 日本移民 疾病 日本人 非美国出生 美国出生 美国白人 食管癌（男） 胃癌（女） 肠癌（男） 乳腺癌（女） 宫颈癌 脑血管疾病 动脉硬化性心脏病

Department of Epidemiology Public Health College of Harbin Medical University 104 小结  疾病频率测量指标  疾病流行强度  疾病分布形式 Distribution of disease summary  Frequency of Disease Measurement  Intensity of Epidemic  Dimension distributions of disease

Department of Epidemiology Public Health College of Harbin Medical University 105 谢 谢 Thank You