Teaching Statistics Using Stata Software

Susan Hailpern BSN MPH MSSusan Hailpern BSN MPH MS

Department of Epidemiology and Department of Epidemiology and Population HealthPopulation Health

Albert Einstein College of MedicineAlbert Einstein College of Medicine

Bronx, New YorkBronx, New York

Albert Einstein College of Medicine Clinical Research Training Program Clinical Research Training program Clinical Research Training program

(CRTP) began in 1998(CRTP) began in 1998 Program funded by the NIH under Clinical Program funded by the NIH under Clinical

Research Curriculum Award ProgramResearch Curriculum Award Program

Program Components

CRTP is a 2 year program consisting of two CRTP is a 2 year program consisting of two complementary components:complementary components: Didactic curriculum with emphasis on Didactic curriculum with emphasis on

epidemiology, biostatistics, study design, epidemiology, biostatistics, study design, computer methods, and research ethicscomputer methods, and research ethics

Mentored experience in clinical research Mentored experience in clinical research leading to masters thesisleading to masters thesis

Program Description:

Program provides future investigators (physicians) with Program provides future investigators (physicians) with basic and applied knowledge in core disciplines of clinical basic and applied knowledge in core disciplines of clinical investigation:investigation: BiostatisticsBiostatistics EpidemiologyEpidemiology

Students learn how toStudents learn how to design clinical research studiesdesign clinical research studies ensure that high ethical standards are metensure that high ethical standards are met organize study team organize study team apply and obtain fundingapply and obtain funding collect, manage and analyze datacollect, manage and analyze data report resultsreport results

Statistical Software

SPSSSPSS SPSS has been used since the start of CRTPSPSS has been used since the start of CRTP

Pull-down menus were thought to be easy to Pull-down menus were thought to be easy to use and learnuse and learn

Students were easily successful in using Students were easily successful in using SPSS software and obtaining statistical SPSS software and obtaining statistical resultsresults

As students progressed in statistical analyses As students progressed in statistical analyses and clinical research, SPSS was found to be too and clinical research, SPSS was found to be too limited in scopelimited in scope

Alternative software was soughtAlternative software was sought

Statistical Software

STATA (and Stat/Transfer v.7)STATA (and Stat/Transfer v.7) Stata was taught in the CRTP for first time in Stata was taught in the CRTP for first time in

Summer ‘04 using Version 8Summer ‘04 using Version 8 Stata was chosen because Stata was chosen because

It has an excellent reputation It has an excellent reputation It is easy to useIt is easy to useAddition of new pull-down menus (version Addition of new pull-down menus (version

8) was attractive feature and was thought to 8) was attractive feature and was thought to make learning software easier for studentsmake learning software easier for students

Statistical Software

STATA (continued)STATA (continued) It It has substantially wider range of procedures has substantially wider range of procedures

and optionsand options than SPSS than SPSSMultinomial and ordinal logistic regressionsMultinomial and ordinal logistic regressionsFrailty models for multivariate survival Frailty models for multivariate survival

analysis (semi-parametric and parametric)analysis (semi-parametric and parametric)Immediate commands Immediate commands

Teaching Stata

Interesting challenge: instructors teaching Interesting challenge: instructors teaching statistics with Stata come from very different statistics with Stata come from very different backgroundsbackgrounds

Senior instructor has had extensive experience Senior instructor has had extensive experience using SPSS and is a relative newcomer to Stata. using SPSS and is a relative newcomer to Stata.

Other instructor has had extensive experience Other instructor has had extensive experience using Stata, but with expertise in writing Stata using Stata, but with expertise in writing Stata programs (unfamiliar with using “pull-down” programs (unfamiliar with using “pull-down” menus in version 8). menus in version 8).

Teaching Stata

Students were asked to install software prior to Students were asked to install software prior to first class first class All students used Windows 98, 2000, or XP All students used Windows 98, 2000, or XP All had some computer experienceAll had some computer experience

Brief introduction to the software was distributed Brief introduction to the software was distributed prior to first classprior to first class Description of the windowsDescription of the windows Variable storage typesVariable storage types Most importantly: how to get Help!Most importantly: how to get Help!

Teaching Stata: First Class

Stata Structure Stata Structure Windows: Data Editor, Results, Review, Variables, Windows: Data Editor, Results, Review, Variables,

Command, ViewerCommand, Viewer Menus and SyntaxMenus and Syntax

Course was taught primarily using pull-down menusCourse was taught primarily using pull-down menus Data FileData File Data structure: Files, Variables, SubjectsData structure: Files, Variables, Subjects Variable Elements: Name, Type, Format, Label, Variable Elements: Name, Type, Format, Label,

Values (labels), Missing Values (labels), Missing Descriptive StatisticsDescriptive Statistics

Teaching Stata: Second Class

Modifying Variables and Subsets and ConditionsModifying Variables and Subsets and Conditions Creating new variables using: gen and replaceCreating new variables using: gen and replace FunctionsFunctions Recoding recode, gen, encode, decodeRecoding recode, gen, encode, decode if , in, sort, drop, keep, save if , in, sort, drop, keep, save

Comparison of means and medians: one and two sampleComparison of means and medians: one and two sample Comparing means and medians for >2 groups: oneway Comparing means and medians for >2 groups: oneway

anova and Kruskal-Wallisanova and Kruskal-Wallis Comparing categorical data 2x2, 2x k tables, ordered Comparing categorical data 2x2, 2x k tables, ordered

categories, RR and ORcategories, RR and OR

Teaching Stata

Additional weekly lab session was added Additional weekly lab session was added Review Review Learn additional nice features of StataLearn additional nice features of Stata

Immediate commandsImmediate commandsDate functionsDate functionsDo fileDo fileGraphingGraphing

Teaching Stata: Third Class

File handling:File handling: use, clear, importing filesuse, clear, importing files merge merge updateupdate appendappend collapse, reshape collapse, reshape

Correlation & Linear RegressionCorrelation & Linear Regression

Teaching Stata: Fourth Class

Multivariate Analyses: Multivariate Analyses: Multiple Linear RegressionMultiple Linear Regression Two-way AnovaTwo-way Anova Interpreting the outputsInterpreting the outputs

Teaching Stata: Fifth Class

Statistical power and sample size using Statistical power and sample size using NCSS/PASS softwareNCSS/PASS software

ReviewReview

Success

Stata statistical software was easy to teachStata statistical software was easy to teach At the end of 6 week summer session At the end of 6 week summer session

students were successful in learning and students were successful in learning and using Statausing Stata

Failures

None!None!

Recommendations for Next Year

Use Stata for power and sample size Use Stata for power and sample size calculations calculations

Continue to teach Stata softwareContinue to teach Stata software This was a terrific success!This was a terrific success!

Interesting Problems

Largest problem encountered was Largest problem encountered was communicating with mentors and communicating with mentors and statisticians unfamiliar with Statastatisticians unfamiliar with Stata

Student Wishes and Grumbles

THE BIG GRUMBLETHE BIG GRUMBLE Windows do not “hang together”Windows do not “hang together” Windows were all over the screenWindows were all over the screen Windows sometimes got “lost”Windows sometimes got “lost”

Student Wishes and Grumbles

Wishes - Students would likeWishes - Students would like ““Un-do” buttonUn-do” button Ability to order variables as desired, and then Ability to order variables as desired, and then

return to original ordering return to original ordering Description of statistical tests Description of statistical tests

As in SPSS where placing the cursor over As in SPSS where placing the cursor over the test will give a brief description of the the test will give a brief description of the statistical teststatistical test

Data window to remain “open” while running Data window to remain “open” while running commands (as in SPSS)commands (as in SPSS)

Any Questions?