社会医学8-课件

社会医学8 ppt课件Epidemiology (Schneider)TOPICn死亡率n潜在寿命损失年-PYLLn伤残调整生命年-DALYn质量调整生命年-QALYn预期寿命-LEn健康预期寿命-HLEEpidemiology (Schneider)1.Mortality OutcomesnCrude rate:nThe number of events in a population over a given period of time,usually a calendar yearnCrude rates reflect the probability of an eventnAs the probability of death increases with age,the crude death rate reflects the age structure of the populationEpidemiology (Schneider)Mortality Outcomes(cont.)Example:1980The larger crude death rate in Florida reflects the larger population of elderly in that state.LocationDeathsPopulationCrude Death Rate per 1,000Florida111,11410,194,00010.9Alaska1,830416,0004.4Epidemiology (Schneider)Calculation PracticeCalculate cause-specific and age-specific lung cancer death ratesWhat information will you need?Epidemiology (Schneider)Lung Cancer Deaths by Age Group,United States,199515,420188,500,741Total12,35631,078,76045-542,70942,467,71935-4430340,873,13925-344135,946,63515-241138,134,4885-14Lung Cancer DeathsPopulationAge(years)How would you calculate the cause-specific lung cancer death rate?How would you calculate age-specific lung cancer death rates?Epidemiology (Schneider)Lung Cancer Deaths by Age Group,United States,199515,420 xxx188,500,741Total12,3562,7093034111Lung Cancer Deaths12,356/31,078,760=39.762,709/42,467,719=6.38303/40,873,139=0.7441/35,946,635=0.1111/38,134,488=0.03Age-Specific Lung Cancer Death Rate31,078,76045-5442,467,71935-4440,873,13925-3435,946,63515-2438,134,4885-14PopulationAge(years)What inferences can you make from these age-specific rates?Cause Specific Rate=(15,420/188,500,741)x 100,000 =8.18/100,000Epidemiology (Schneider)Creating a cause-specific,age-adjusted death rate using direct standardization(3)x(4)=(5)(4)(1)/(2)=(3)(2)(1)226,500,000 xxx45,000115Total25,700,00015,00010065+140,300,00025,0001019-6460,500,0005,00050-18Expected 1980 U.S.Standard PopulationAge Specific Rate(per 1000)Population at riskCancer DeathsAgeEpidemiology (Schneider)Creating a cause-specific,age-adjusted death rate using direct standardization(3)x(4)=(5)(4)(1)/(2)=(3)(2)(1)288,039,000226,500,000 xxx45,000115Total171,419,00025,700,0006.6715,00010065+56,120,000140,300,0000.4025,0001019-6460,500,00060,500,0001.005,00050-18Expected 1980 U.S.Standard PopulationASR/1000Population at riskCancer DeathsAgeAge-Adjusted Rate(288,039,000/226,500,000)x 1000 1.27 per 1,000Crude Rate(115/45,000)x 1000 2.56 per 1,000Epidemiology (Schneider)Comparing crude and age-adjusted ratesnIf crude rate decreases after adjustment,the study population is older than the standard population(Crude rate age-adjusted rate study population is older)nIf crude rate increases after adjustment,the study population is younger than the standard population(Crude rate age-adjusted rate study population is younger)Epidemiology (Schneider)2.Potential years of life lost，PYLLnReference age=75nAge at death=60,PYLL(75)=15nAge at death=0.5,PYLL(75)=74.5nAge at death=80,PYLL(75)=0=eiiidaPYLL1Epidemiology (Schneider)1974年加拿大主要疾病死因构成与PYLL构成比较 死亡原因 PYLL(170岁)死亡(170岁)PYLL(年数)%死亡例数%全部死因 1312675.0 100.0 77440 100.0 交通事故 239238.5 18.2 5864 8.0缺血性心脏病 198327.5 15.1 19205 26.2 其他事故 165264.5 12.6 4795 6.5自杀 84195.0 6.4 2716 3.7 消化系统肿瘤 56667.0 4.3 5186 7.1 呼吸系疾病 50264.0 3.8 3425 4.7呼吸系肿瘤 48079.5 3.7 4444 6.1 脑血管病 45418.0 3.5 4068 5.5肝硬化 37954.0 2.7 2204 3.0乳腺癌 30919.0 2.4 2108 2.9 神经系统疾病 29634.0 2.3 1119 1.5 (Frerichs,1986)19741974年加拿大主要疾病死因构成与年加拿大主要疾病死因构成与PYLLPYLL构成比较构成比较 死亡原因死亡原因 PYLL(1PYLL(17070岁岁)死亡死亡(1(17070岁岁)PYLL(PYLL(年数年数)%)%死亡例数死亡例数%全部死因 1312675.0 100.0 77440 100.0 交通事故 239238.5 18.2 5864 8.0缺血性心脏病缺血性心脏病 198327.5 15.1 19205 26.2 198327.5 15.1 19205 26.2 其他事故 165264.5 12.6 4795 6.5自杀 84195.0 6.4 2716 3.7 消化系统肿瘤消化系统肿瘤 56667.0 4.3 5186 7.1 56667.0 4.3 5186 7.1 呼吸系疾病 50264.0 3.8 3425 4.7呼吸系肿瘤呼吸系肿瘤 48079.5 3.7 4444 6.1 48079.5 3.7 4444 6.1 脑血管病 45418.0 3.5 4068 5.5肝硬化 37954.0 2.7 2204 3.0乳腺癌 30919.0 2.4 2108 2.9 神经系统疾病 29634.0 2.3 1119 1.5 (Frerichs,1986)Epidemiology (Schneider)n指从发病到死亡所损失的全部健康寿命年，包括因早死所致的寿指从发病到死亡所损失的全部健康寿命年，包括因早死所致的寿命损失年命损失年(YLL)和疾病所致伤残引起的健康寿命损失年和疾病所致伤残引起的健康寿命损失年(YLD)两部分。两部分。nDALY=YLL+YLDnYLL =N LnYLD=IDWLnDALY是一个定量计算因各种疾病造成的早死与残疾对健康寿命是一个定量计算因各种疾病造成的早死与残疾对健康寿命年损失的综合指标，是测算疾病负担的主要指标之一。据此可年损失的综合指标，是测算疾病负担的主要指标之一。据此可确定危害健康严重的疾病和主要卫生问题。确定危害健康严重的疾病和主要卫生问题。第一节第一节 疾病频率测量疾病频率测量3.伤残调整寿命年伤残调整寿命年(disability adjusted life year,DALY)Epidemiology (Schneider)Epidemiology (Schneider)Epidemiology (Schneider)WHO model of health transition(1984)Epidemiology (Schneider)What are DALYs?nDALYs=Disability Adjusted Life Years nA common measurement unit for morbidity and mortalitynFacilitates comparisons of all types of health outcomesEpidemiology (Schneider)CLICK TO ENLARGEEpidemiology (Schneider)How are DALYs constructed?nA DALY is a health outcome measure with two main componentsnQuality of life reduced due to a disabilitynLifetime lost due to premature mortality.Epidemiology (Schneider)DALYs due to living with disability(Red area measures DALYs.Red+white is a“normal”life)82,5 YEARSNO DISABILITYEpidemiology (Schneider)DALYs due to early death(Red area measures DALYs.Red+white is a standard life)NO DISABILITY82,5 YEARSEpidemiology (Schneider)DALYs due to disability and premature death combined.NO DISABILITY82,5 YEARSEpidemiology (Schneider)Calculation of DALYs(age-weighting and discounting are omitted for didactic reasons)nThe calculation of DALYs of a woman who has been deaf since she was 5 and dies when she is 50:(Disability weight of deafness is set at 0.33):nNumber of healthy life years the disability weight of full health(0)+life years with disability(50)disabilty weight for deafness(0,33)+life years lost(30)the weighting of death(1)n5 0+45 0,33+32.5 1=47.35 DALYsEpidemiology (Schneider)4.What is a QALY?nA quality-adjusted life-year(QALY)takes into account both the quantity and quality of life generated by healthcare interventions.It is the arithmetic product of life expectancy and a measure of the quality of the remaining life-years.nQ(preferences score)L(life years)=Quality-Adjusted Life YearsEpidemiology (Schneider)Quality-Adjusted Life YearsAB00.60.71.0生命质量生命质量69年年生命数量生命数量A 6年年 QoL为为0.7=4.2QALYsB 9年年 QoL为为0.6=5.4QALYsB-A=1.2 QALYsEpidemiology (Schneider)Quality-Adjusted Life YearsGold,MR et al(Eds.)Cost-effectiveness in Health and Medicine(1996)QLEpidemiology (Schneider)Quality-Adjusted Life YearsAB死亡死亡 0新药干预新药干预无干预无干预获得的生命获得的生命质量年质量年（QALY）完全完全健康健康 1.0生存期生存期Epidemiology (Schneider)DALYs and QALYsnDALY is a modification of QALY(Quality Adjusted Life Years).nBoth concepts combine information about length of life and quality of life.nA DALY is a negative QALY.Epidemiology (Schneider)Relation between QALYs and DALYsDALYs=healthy years lost QALYs=healthy years gainedNO DISABILITY82,5 YEARSEpidemiology (Schneider)DALYs and QALYsnIn the DALY approach,the years are disability weighted on a scale from zero,which indicates perfect health (no disability),to one,which indicates death.nIn the QALY approach,the scale goes the opposite way:A quality weighting(sometimes called“utility”)of 1 indicates perfect health,whereas 0 indicates no quality of life,and is synonymous to death.Epidemiology (Schneider)Epidemiology (Schneider)Discounting and Age weighting nDiscounting nthe value of a life year now is set higher than the value of future life yearsnAge weightingnlife years of children and old people are counted lessEpidemiology (Schneider)Age-weightsEpidemiology (Schneider)Global Burden of Disease age-weighting function Epidemiology (Schneider)The effect of age-weighs and discountingEpidemiology (Schneider)Calculating DALY score,with age weighting and discounting.nGirl,5 years old,with below-knee amputation who lives until she is 82,5:nDALYs=life years lived with disease(77,5)disability weight(0,3)age-weight(a1)discounting factor(d2)n77.5 0.3 a1 d2=10.5 DALYsEpidemiology (Schneider)The youngnThe 5-year-old girl in the example above yielded 10,5 DALYs.nHowever,the DALY score without age-weight and discounting would be n77.5 0.3=23,3 DALYs nThis result is twice as high,and would give her a higher priority.Epidemiology (Schneider)5.Life Expectancy(LE)nThe expected number of years to be lived from age x(typically from birth)nMeasure of population healthnLE is increasing over time in Asia and around the worldEpidemiology (Schneider)Life expectancy at birth:Selected Asian countries,1990-2002World Bank Indicators,2003Epidemiology (Schneider)Percent of total population aged 65 years and older,1990-2002World Bank Indicators,2003Epidemiology (Schneider)6.Healthy life expectancy(HLE)nThe expected number of years to be spent in good health from age xn“Health”usually refers to functional abilities or self-rated healthnAdvantage of HLE:ease in interpretationnLE 65=20.9 yrs*;HLE 65=18.3 yrs*n%of LE in good health:HLE/LE=.88*Females in Japan,1995Epidemiology (Schneider)Estimating healthy life expectancy using the Sullivan(1971)method and life tables:DPR=Disability prevalence rate for age x from survey data1.Lx(hs)=(1-DPR)*Lx person years spent in health2.Tx(hs)=x=t L x(hs)+t total person years lived in health3.ex(hs)=Tx(hs)/lx healthy life expectancyNote:hs=healthy stateEpidemiology (Schneider)LE at birth and age 65(UK)2.6 years men 1.7 years women 2.0 years men 1.2 years womenEpidemiology (Schneider)LE at birth(Europe)Epidemiology (Schneider)Life Expectancy at birthWorld Health Report 2006Epidemiology (Schneider)Life Expectancy(LE)and Healthy Life Expectancy(HLE),China,1987Females are advantaged with more years of life and more years of healthy life.Grab et al.,1991Epidemiology (Schneider)Similar trends in other Asian countries:Life Expectancy 65Healthy Life Expectancy 65MalesMalesFemalesEpidemiology (Schneider)Percent of life to be spent in health 65,(HLE/LE)China,1987Males have the advantage with a greater percent of healthy life years.Grab et al.,1991Epidemiology (Schneider)MalesFemalesPercent of Healthy Life 65 in selected Asian countries:Taiwan,1986Burma,1989China,1992Taiwan,1991China,1987Malaysia,1984S.Korea,1984Indonesia,1989N.Korea,1989Sri Lanka,1989Thailand,1989Thailand,1986 SRHThailand,1995 SRHThailand,1996Singapore,1995Epidemiology (Schneider)Quality of LifeCountryHealthy Life ExpectancyLife ExpectancyJapan7582Australia7380Canada7280Sweden7380United Kingdom7178United States6977Cuba6877India5462Kenya4450Nigeria4245Epidemiology (Schneider)A Global Perspective GDP&Life Expectancy CIA World Factbook/World Health Report,2006Epidemiology (Schneider)Healthy LivingDisability Free or HeAlthy Life Expectancy(HALE)(2000)and Life Expectancy(LE)at birth.Source:Health For All Database.WHO Regional Office for Europe.Copenhagen,Denmark.Epidemiology (Schneider)7.伤残调整期望寿命（DALE）n定义：定义：将在非完全健康状况下生活的年数，经过伤残严重性权重转换，转化成相当于在完全健康情况下生活的年数.n计算：计算：DALEx=LEx-DALYxn意义意义n比较不同人群健康状况n确定重点人群和重点防治疾病n衡量人群健康水平的公平性n提供测量非死亡性健康状况的有效方法Epidemiology (Schneider)WHO2009世界世界卫卫生生统计统计:卫生费用卫生费用(06)会员国会员国卫生总费用卫生总费用占占GDP的的%政府一般性卫生政府一般性卫生投入占卫生总费投入占卫生总费用的比例用的比例%个人卫生支出个人卫生支出占卫生总费用占卫生总费用的比例的比例%人均政府费用人均政府费用PurchasingPower Parity$人均卫生总费用人均卫生总费用PurchasingPower Parity$全球8.757.642.4455790中国4.640.759.388216美国15.345.854.230766719日本8.181.318.720972242古巴7.791.68.4617674俄国5.363.236.8441698Epidemiology (Schneider)WHO2009世界世界卫卫生生统计统计:全球健康指标全球健康指标(07)会员国会员国期望寿命期望寿命LY健康期望健康期望寿命寿命HALE新生儿死亡率新生儿死亡率/1000婴儿死亡率婴儿死亡率/10005岁以下死亡率岁以下死亡率/1000成人死亡率成人死亡率(15-60)/1000全球男性男性65女性女性70男女男女68男性男性58女性女性61男女男女5928男性男性48女性女性45男女男女46男性男性67女性女性66男女男女67男性男性217女性女性147男女男女183中国男性男性72女性女性75男女男女74男性男性65女性女性68男女男女6618男性男性16女性女性22男女男女19男性男性19女性女性26男女男女22男性男性142女性女性85男女男女115古巴男性男性76女性女性81男女男女78男性男性68女性女性71男女男女694男性男性5女性女性4男女男女5男性男性7女性女性6男女男女6男性男性124女性女性79男女男女1102日本男性男性79女性女性86男女男女83男性男性73女性女性78男女男女761男性男性3女性女性2男女男女3男性男性4女性女性3男女男女4男性男性88女性女性44男女男女66俄国男性男性60女性女性73男女男女66男性男性55女性女性65男女男女607男性男性11女性女性8男女男女10男性男性14女性女性11男女男女12男性男性448女性女性164男女男女312美国男性男性76女性女性81男女男女78男性男性68女性女性72男女男女704男性男性7女性女性6男女男女6男性男性8女性女性7男女男女8男性男性135女性女性80男女男女108