Teaching Statistics By Example.ppt

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1、Teaching Statistics By Example,Lisa M Sullivan, PhD Boston University,Outline,Statistics in the News The Introductory Statistics Requirement Course Content Recent Efforts at Reform Modifications? Examples for Specific Topics,News Week of May 29, 2006,Preserve brain function with spicy foods.Kicking

2、your food up a notch with spices could preserve brain function and keep your brain sharp and strong as you age.Turmeric, a spice that lends curries their yellow tint, can curb mental decline and even slow the effects of neurodegenerative diseases such as Alzheimers.,News Week of May 29, 2006,Educati

3、on linked to better fathers studyU.S. data shows trend between education and time spent with kidsWell-educated men tend to make better fathers, according a new U.S. government report on fatherhood.,News Week of May 29, 2006,U.S. Releases Bird Flu Response Plan - Details outline containment policies;

4、 focus on worst-case scenarios may spread fear, experts sayBreast Cancer Survivors Lax About Mammograms - Only 33% get them annually for five years after diagnosis, study finds,News Week of May 29, 2006,The FDA issued a long-awaited approval on a new human growth product.Approval of Omnitrope, made

5、by Sandoz, was announced Tuesday in a statement on the FDAs Web site.Omnitrope, also known as somatropin, is a hormone used to treat growth disorders in children and adults.,Statistics Requirement,Numerical literacy Provide quantitative foundations for study in specific disciplines Understand and in

6、terpret data Perform independent research,Careers in Statistics,Business and Industry (Manufacturing, Marketing, Engineering) Health and Medicine (Public Health, Clinical Trials, Epidemiology, Genetics, Health Communication) Government (Census, Surveys) Academia Social Sciences Health InsuranceDeman

7、d for statisticians far exceeds supply today and this is expected to increase through 2008.,The Introductory Statistics Course,Difficult and frustrating for students Difficult and frustrating for instructorsHundreds of thousands of undergraduates across a variety of majors are required to take stati

8、stics - most not mathematically inclined,Typical Course Content,Descriptive Statistics Classification of Variables Means, Standard Deviations, Medians Graphical Displays Principles of Probability Probability Models Binomial, Poisson, Normal Central Limit Theorem,Course Content,Estimation Point Estim

9、ates Margin of Error Precision Hypothesis Testing Hypotheses Test Statistic Critical Region Level of Significance, P-values,Course Content,Associations Between Variables Regression Analysis Analysis of Variance Chi-Square Tests,Reforms in Undergraduate Education in Statistics,NSF funded various proj

10、ects to improve teaching of undergraduate statistics courses May 1999 the ASAs Undergraduate Statistics Education Initiative (USEI) was launched,Focus of the Reform,Emphasize concepts over procedures Teach students to: Formulate research questions Collect data Analyze data Interpret results,Focus of

11、 the Reform,Gain experience working with real data Focus on active learning Build communication skillsMAJOR FOCUS on statistical literacy/ statistical thinking,Statistical Thinking,Process of using wide ranging and interacting data to understand processes, problems, and solutions. The opposite of on

12、e factor at a time, where ones natural born tendency is to change one factor and “see” what happens. Statistical thinking is the tendency to want to understand how several control factors may be interacting at once to produce an outcome. Common cause variation becomes your friend and special cause v

13、ariation your enemy. Attribute judgments of good and bad are replaced with estimates of significance with given confidence.-Six Sigma http:/ Thinking,Recognize and attempt to understand/explain variation The process of asking a “good” question, collecting, analyzing and interpreting data and appropr

14、iately recognizing limitationsHow do we teach statistical thinking?,Recommendations for Instructors,Provide working examples that include questions and processes to solve statistical problems Allow students to practice using statistical thinking with open-ended questions and problems Use technology

15、to collect, manage and analyze data,Recommendations for Instructors,Use real data Choose data and questions that are of interest to students Reduce content to focus on key concepts in greater detail,Whats Missing,Study Design Issues and Implications Real Data Interpretation of Results Practical Impl

16、ications Limitations of Inferences Statistical Computing,Limitations/Interpretation,Association is not causation Statistical significance is not practical importance Lack of statistical significance does not imply no difference Understand how to interpret news stories/articles with statistical infor

17、mation,Modifications?,Include design and analysis issues in curriculum Sharpen skills in interpretation of results Include projects with real data Stress communication skills Focus more on big picture,Big Picture,What is a statistical study? How is sample constructed? What are the key questions? How

18、 is information collected analyzed interpreted? What makes a good study? A poorly analyzed study can be re-analyzed. A poorly designed study cannot be re-designed.,Biostatistics,A specialized branch of applied mathematics/statistics that deals with the statistical evaluation of experimental research

19、 or clinical trial results. Statistical applications in the medical or public health arena.,Biostatistics,Mathematics/Statistics,Medicine/Public Health,Biostatistics,Computer Science,Examples,What proportion of college students drink alcohol, use illegal drugs? Should driving age be increased? Are c

20、ell phones safe for children?How can we address these questions?,Research Teams,Principal Investigator (Clinicians, Scientists) Statistician/Biostatistician Co-Investigators Project Manager Statistical Programmers Research Assistants,Statisticians Role on Team,Develop Study Design Research question

21、Study sample Sample size Enrollment/Follow-up strategies On-going monitoring Perform Interim and Final Analysis Interpret and Report Results,Cell Phones for Children?,University of Washington scientist states 70-80% of the energy emitted from the antenna of a mobile phone is absorbed in the head: Ch

22、ildrens skulls are thinner and their growing brains may be much more susceptible to radiation exposure. FDA states that scientific evidence does not show a danger to users of wireless communication devices including children.,Study of Cell Phone Safety,What is the outcome? What is exposure/risk fact

23、or? How can we assess relationship between cell phone use and health outcomes? Study Design Data Collection and Analysis Interpretation/Attribution,Issues for Biostatisticians,Children - Obesity, Immunizations, Asthma, Autism Adolescents Alcohol & Tobacco Use, Depression, STDs, Traffic Accidents. Ad

24、ults Cancer, CVD, Substance Abuse, HIV/AIDS, Mental HealthWhat is #1 killer of men and women in US? What are the risk factors?,Research Set Context,Framingham Heart Study Pharmacologic Clinical Trials in Children with Autism Effect of Alcohol Exposure in Pregnancy on SIDS,The Framingham Heart Study,

25、5000+ men and women enrolled in 1948 Longitudinal cohort study Exams every 2 years for cardiovascular risk factors - surveillance Ancillary studies hearing, exercise, nutrition, neurological studies 5000+ offspring & spouses enrolled in 1976 Third generation enrolled in 2002http:/www.nhlbi.nih.gov/a

26、bout/framingham/,Milestones from Framingham,1960 Cigarette smoking increases risk of heartdisease 1961 Cholesterol & blood pressure increase risk ofheart disease 1967 Physical activity reduces risk of heart disease,obesity increases risk of heart disease 1970 High blood pressure increases risk of st

27、roke 1978 Psychosocial factors increases heart disease 1988 High levels of HDL cholesterol reduces risk ofdeathMore than 1500 scientific papers published,Framingham Study Risk Functions,Risk prediction models Predict likelihood that a person will have coronary heart disease in the next 10 years Mode

28、ls designed to include risk factors that are readily available Age, blood pressure, cholesterol, smoking, diabetes, treatment for hypertension & high cholesterol, obesityRisk Calculator http:/ Trial in Children with Autism,Autism-brain disorder usually diagnosed before age 3 that affects communicati

29、on, social interaction, and creative play. Affects over 500,000 children in the USTrial to assess the efficacy of drug treatment in reducing repetitive behaviors Children randomized to receive study drug or placebo,Clinical Trial in Children with Autism,144 children with autism aged 5-17 years follo

30、wed every 2 weeks for 12 weeks for improvements in repetitive behaviorsIssues Randomization/Blinding Measurement of outcome (child, parent, teacher) Safety/Ethical issues,Effect of Alcohol Exposure in Pregnancy on SIDS,SIDS Unexplained infant death before 1 year of life Extremely high rates of SIDS

31、among American Indians in Northern Plains of North and South Dakota and in Cape Town South Africa High rates of alcohol consumption,Effect of Alcohol Exposure in Pregnancy on SIDS,SIDS 0.57/1000 in US3.4/1000 in Northern Plains3.5/1000 in Cape TownIn US 13% of women report drinking alcohol in pregna

32、ncy58% in Northern Plains41% in Cape Town,Effect of Alcohol Exposure in Pregnancy on SIDS,Study of 12,000 pregnant women in Northern Plains and Cape Town Assess relationship between alcohol and SIDS Issues Measuring alcohol exposure Ethical Issues e.g., Autopsies,Examples for Specific Topics,Conditi

33、onal Probability Performance of screening tests for prenatal diagnosis, prostate cancer, breast cancer, HIV,Prenatal Diagnosis,Your family is pregnant should you have a screening test?Standard of Care in the US is serum screen 68% sensitivity 5% false positive rate,Performance Characteristics of Scr

34、eening Tests,Disease + Disease Test + a b Test - c d,Performance Characteristics,Sensitivity = True Positive Fraction = P(Test + | Disease)False Positive Fraction = P(Test + | No Disease),For the Patient,Positive Predictive Value = P(Disease | Test +)Negative Predictive Value = P(No Disease | Test -

35、),Examples for Specific Topics,Normal Probability Model Percentiles Height, Weight, BMI for agehttp:/www.cdc.gov/growthcharts/,Statistical Inference,Estimation and Hypothesis Testing Clinical Trials Search for clinical trials Recent results (press releases and scientific articles)http:/www.clinicalt

36、rials.gov/,Introductory Statistics,Big Picture and Make it Real! Real Data Relevant Examples Focus on Interpretation Practical Importancehttp:/ Programs at Boston U www.bu.edu,BA in Mathematics/Statistics Minor in Applied StatisticsSummer Institute for Training in BiostatisticsMA in Biostatistics PhD in BiostatisticsMinor in Public Health (Biostatistics, Epidemiology, Environmental Health, International Health, Health Law, Maternal and Child Health, Health Services, Social and Behavioral Science),