15多元线性回归.ppt

1、Health Statistics,卫生统计学,1,Teaching Group,Chuanhua Yu（宇传华），ProfessorJing Sun （孙静）， Lecture Lu Ma （马露） ， Lecture,2,Textbook Book,卫生统计学 （第六版），2008.5主编： 方积乾出版：人民卫生出版社卫生统计学学习指导 主编： 方积乾出版：人民卫生出版社,3,Reference Books,Bowers David. Medical Statistics from Scratch:An Introduction for Health Professionals (Seco

2、nd Edition). John Wiley & Sons Ltd, 2008.LE CHAP T. Introductory Biostatistics. John Wiley & Sons Ltd, 2003.Petrie Aviva, Sabin Capoline. Medical Statistics at glance. Blackwell Science Ltd.,2000.方积乾主编.生物医学研究的统计方法. 北京：高等教育出版社，2007.6（ISBN：9787040208412），604页,4,Method of learning,Preparation Attending

3、 Recording ReviewingPractice,5,Exercise requirements,TranslationWriting in EnglishDetailed processSubmit on time,6,Introduction,绪论,7,Chapter 1,Contents,Statistics & Health statisticsTypes of dataBasic concepts of statistics,8,New words,StatisticsBiostatisticsHealth statisticsQuantitative dataQualita

4、tive dataNumerical dataCategorical data,9,统计学生物统计学卫生统计学定量数据定性数据数值型数据分类型数据,Continuous dataDiscontinuous dataDiscrete dataBinary dataOrdinal dataNominal dataVariableRandom eventProbability,10,连续型数据非连续型数据 离散型数据二分类数据顺序型数据名义型数据变量随机事件概率,PopulationSampleSample sizeRandom samplingSampling errorParameterStat

5、isticDescriptive analysisInferential analysis,11,总体样本样本量随机抽样抽样误差参数统计量描述分析推断分析,1,What is statistics?,12,statistics,Data analysis,13,Basic idea of statistics,Data collection: 100 students 200 students 30 short-sight 40 short-sightInterpretation: 30% abnormal 20% abnormal,Conclusion: The eyesight of st

6、udents in city Aare bad than those in city B.,Evaluation: 1) Is this conclusion correct?2) What is the reliability (可信度) of the conclusion?,City A City B,Statistics （统计学）: It is a branch of applied mathematics that refers to the collection and interpretation of data, and evaluation of the reliabilit

7、y of the conclusions based on the data.,14,Biostatistics （生物统计学）: It is a branch of the statistics, in which the data are derived from the biological sciences and medicine.,15,Health Statistics It is a branch of the statistics, in which the data are derived from the medical researches about health c

8、are, health services, diseases prevention etc.,16,Application of data analysis in the medical research,What is the average birth-weight of infants born in Hubei province?Is there any differences of curative effect between two types of medicine?Which risk factors impact on the occurring of stomach ca

9、ncer? How to predict the likelihood of recovery from a disease (prognosis of a disease)?,17,18,Example of detecting a complex relationship between factors,physicalactivity,eating,drinking,smoking,social economic status,enduredglucose,bloodpressure,weight,cholesterol,diabetes,coronary heart disease,e

10、nvironment,life style,endogeneousfactors,diseases,19,The position of statistical analysis in medical research,doctor,patients,data,evaluatetreatment,statisticalanalysis,improved knowledge,feedback,An important and necessary course for medicine students,It is an important It is also a necessary subje

11、ct, like the medical imaging, taken part in an important role for improving the medical science.,20,History of statistics,Beginning in 17th century, it is an application branch of probability theory. Calculators (60 decade of 20th) made the basic statistical analysis more applicable.Computers (80 de

12、cade of 20th) made the multi-variate statistical analysis more applicable,21,2, Types of data,Data （数据）:It is an information derived from the different measuring devices.,22,Source of data,Routine recordsSurveyed recordsExperimental recordsExternal information,23,24,Types of data,data,Continuous ( 连

13、续) Discontinuous (非连续)Discrete (离散),Ordinal ( 顺序),Nominal (名义),Quantitative(定量),Qualitative(定性),Numerical(数值),Categorical(分类),Quantitative or numerical data,Quantitative / numerical data （定量 / 数值数据）:It is the data with unit (or scale) and origin .eg, blood pressure - continuous white blood cells - d

14、iscrete,25,Qualitative or categorical data,（定性 / 分类数据）:It is the data without unit (or scale) and origin . eg, sex -binary (二分类) likeness -ordinal (有序多分类) occupation -nominal (无序多分类),26,3, Basic concepts of statistics,Variable（变量）:It is a set of data observed from different persons, place, things, e

15、tc, and it describes a certain characteristic.,27,28,Data and variable,Event & random event,Event （事件）:Suppose something has k different outcomes, and only one outcome can occurs at a time, then each possible outcome is called as an event.,29,eg, tossing a two-sides coin: head or tail.,Random event

16、（随机事件）:If the outcome of an event is unknown before trial, then this event is called as a random event.,30,eg, throwing a 6-side die: 1,2,3,4,5,6.,Probability （概率）:It is a measure of the likelihood of a random event occurring, using “P” represents it, and 0P1.,31,32,1) tossing a two-sides coin: head

17、 or tail.,head,P (head facing up) = 1/2,2) throwing a six-sides die: 1,2,3,4,5,6 faces.,2,1,3,P (number 6 facing up) = 1/6,33,Population,population,The blood glucose concentration of female aged 25-39 in Hubei province,The weight ofboys aged 5-10 year olds in Wuhan city.,Population （总体）:All collecti

18、on of measurements about which one wish to draw conclusions.,34,35,Sample,Sample （样本）:It is a subset of population, and the conclusions about the population can be drawn from it.Sample size （样本量）: nThe number of individual observations in a sample.,36,37,Random sample,sample,A subset of population,T

19、he conclusions about the population can be drawn from the sample.,Each member of the population has an equal chance to be selected,The selection of any member from population does not influence the selection of any other member.,Random sampling,equal chance,independent each other,Random sample,Rando

20、m sample （随机样本）:Each member of the population has an equal chance to be selected and all samples are independent each other.,38,How to draw a random sample?,There are many methods to draw a random sample, for example:Simple random samplingSystem random samplingClustering random samplingStratified ra

21、ndom sampling,39,Table of random numbers,40,10 09 73 25 33 76 52 01 35 16 35 67 23 48 79 80 93 90 11 16 37 24 20 48 05 64 89 47 42 96 24 80 52 40 37 20 63 61 04 02 08 42 26 80 53 19 64 50 83 03 23 20 90 25 60 15 35 53 47 78,Example: random sampling 10 students from a class with 70 students.Assign ea

22、ch student in the classroom a unique number from 1 to 70.Determine the beginning 2-digits number to be used on the random number table, eg, 1st row and 6th column, the 2-digits number is 76.Read the random numbers from the beginning number, if the random number 70 or =0, then jump to next number, ot

23、herwise, record the number in a paper, if the number is repeated appearing, also jump to next number, do this until a total of 10 different random numbers between 1-70 are recorded.Select the students who has the recorded random number. ie,. The 10 students are those who have the random numbers: 52,

24、 01, 35, 16, 67, 23, 48, 11, 37, 24.,Parameter and statistic,41,population mean,sample mean,What is a good estimate of parameter?,42,parameter,statistic,unknown,known,Types of error,43,error,systematic error(系统误差) -avoidable,random error（随机误差） -unavoidable,Difference between true and estimate.,Sampl

25、ing error （抽样误差）:A type of random error, it is due to the random sampling and the variation between individuals.Random variable（随机变量）:A variable measured with random error.Fixed variable（固定变量）:A variable measured without random error.,44,Types of statistical analysis,Descriptive analysis (描述分析) Collect dataInterpretation of data (draw conclusion)Inferential analysis (推断分析) Evaluate the reliability of the conclusions,45,Summary,Medical statistics Types of dataPopulation and sampleRandom sampling Parameter and statisticRandom event & probability,46,Reading,47,卫生统计学第一章 绪 论,The end,48,