Quantitative Methods for Health Care Professionals PUBH 741 (2013)

Transcription

1 1 Quantitative Methods for Health Care Professionals PUBH 741 (2013) Instructors: Joanne Garrett, PhD Kim Faurot, PA, MPH Assigned Readings: Copies of the class lectures are posted on Sakai under Course Documents and Lectures ; you may want to print them off to bring to class. Read before class. Given the speed with which we will be covering the material, reading ahead will make it easier to keep up. See syllabus for pages (note: starting and stopping points for each class may not always be exact). There also are a few journal articles listed on the syllabus. Suggested Texts: (No required text) See suggested recommendations listed on Sakai Schedule: Time: Tues/Thurs 12:00-2:00 Location: 08/20 09/ Bioinformatics 08/22, 08/27 Stata class; Room 307 Health Sciences Library (HSL), or 1131 Bioinformatics (see syllabus, p.3) 09/05 12/03 G100 Bondurant Grades: Problem Sets: 40% Midterm: 20% Final Exam: 40% Problem Sessions: These sessions will be used to discuss answers to problem sets, as well as any other questions, including computer help. (See the document on Problem Sessions on Sakai under Course Information). Teaching Assistants: Maga Chagomerana Dana Pasquale chago@ .unc.edu dana_pasquale@unc.edu Course Goals: 1) Basics of statistical inference 2) Working knowledge of and ability to critique the most common analyses seen in the medical and other health care literature 3) Familiarity with the overlap between statistical and epidemiological terminology 4) Hands-on experience analyzing data sets from actual studies, thus gaining necessary skills to do many independent data analyses and/or better communicate with biostatisticians 5) Suggestions for writing/submitting journal articles and grant applications

2 2 Software: Class examples and data sets will use Stata 13; Stata is available for use on your own computer via the campus virtual computer lab, or at the Odum Institute in the Davis Library. Personal copies of Stata can be purchased. See Sakai for how to purchase Stata; also will be explained in class. Additional Stata Resources: (main website for Stata) (Brief tutorials on the use of Stata) (UCLA site with helpful Stata information and tutorials) Also Google Joseph Cohen Stata videos good step-by-step videos for absolute beginners

3 3 Part 1: Overview of Data and Statistics Tues 8/20 Class 1 Lecture notes: PUBH741-Part1.pdf; pp Class overview (format, schedule, syllabus, books, data sets, problems, exam, introduction to Stata) Definitions (descriptive/inferential statistics, types of data, graphs) Note on Stata sessions: One-half of the class will attend a Stata session (you only need to attend one session) on 08/22 or 08/27 in the Health Sciences Library. The other half of the class will attend a regular class held in 1131 Bioinformatics. The date you are to attend will be announced on the first day of class (8/20) and will also be posted on Sakai. Everyone will attend the Stata session on 08/29 in 1131 Bioinformatics. Thurs 8/22 Stata session (307 HSL) or Class 2 (1131 Bioinformatics) Lecture notes: PUBH741-Part1.pdf; pp Central tendency and dispersion Normal distributions Central Limit Theorem Tues 8/27 Stata session (307 HSL) or Class 2 repeat of 8/22 class (1131 Bioinformatics) Lecture notes: PUBH741-Part1.pdf; pp Central tendency and dispersion Normal distributions Central Limit Theorem Thurs 8/29 Class 3 Stata: Miscellaneous topics (e.g., Stata on the virtual lab, purchasing Stata, graphs, other topics not covered during the Stata session) Questions and answer session Tues 9/03 Class 4 Lecture notes: PUBH741-Part1.pdf; pp Probability Binomial distribution Elements of statistical inference (population vs. sample, standard error)

4 4 Thurs 9/05 Class 5 Lecture notes: PUBH741-Part1.pdf; pp Elements of statistical inference continued (hypothesis testing, Type I and Type II errors, one or two-tailed tests, confidence intervals, sample size) Part 2: Bivariable Analysis Tues 9/10 Class 6 Problem Set #1 due (Part 1) Lecture notes: PUBH741-Part2.pdf; pp x 2 tables Measures of association (Pearson s chi-square, Fisher s exact test, risk ratios and odds ratios) Thurs 9/12 Class 7 Lecture notes: PUBH741-Part2.pdf; pp ; [skip pp ] Stratified analysis Sample size calculation (difference of two proportions, risk ratios, odds ratios) R x C tables Kappa Article: Viera AJ, Garrett JM. Understanding Inter-observer Agreement: The Kappa Statistic. Fam Med, 2005;37(5): Tues 9/17 Class 8 Review Problem Set #1 Lecture notes: PUBH741-Part2.pdf; pp Comparing two groups (2 sample t-tests) Sample size calculation (difference of two means) Thurs 9/19 Class 9 Lecture notes: PUBH741-Part2.pdf; pp Comparing more than two groups (one-way analysis of variance ANOVA) Multiple testing Two repeated observations (paired t-test) Sample size calculation (paired t-test) 2-sample t-test of differences

5 5 Tues 9/24 Class 10 Lecture notes: PUBH741-Part2.pdf; pp Note: Lecture notes and topics for this class continue below Part 3: Linear Regression 2-sample t-test of differences continued Ranked data non-parametric statistics (Wilcoxon rank-sum, Wilcoxon singed rank, Kruskall-Wallis) Part 3: Linear Regression Tues 9/24 Class 10 (continued) Lecture notes: PUBH741-Part3.pdf; pp Simple linear regression Scatterplot Predictive values Thurs 9/26 Class 11 Problem Set #2 due (Part 2) Lecture notes: PUBH741-Part3.pdf; pp Correlation (Pearson s, Spearman s) Multiple regression (model, interpretation of betas, partial F, predictive values) Article: Maciejewski ML, Diehr P, Smith MA, Herbert P. Common Methodological Terms in Health Services Research. Medical Care, 2002;46(6): Tues 10/01 Class 12 Lecture notes: PUBH741-Part3.pdf; pp Indicator variables (two categories, more than two categories) Thurs 10/03 Class 13 Review Problem Set #2 Lecture notes: PUBH741-Part3.pdf; pp Indicator variables continued (advantages, four category example) Analysis of covariance (ANCOVA; introduction) Tues 10/08 Class 14 Problem Set #3 due (Part 3a) Lecture notes: PUBH741-Part3.pdf; pp Analysis of covariance continued (effect of covariates, examples)

6 6 Thurs 10/10 Class 15 Lecture notes: PUBH741-Part3.pdf; pp Analysis of covariance continued Regression modeling strategies (multiple linear regression, ANCOVA) Tues 10/15 Class 16 Review Problem Set #3 (TA lecture) Thurs 10/17 Fall Break Part 4: Logistic Regression / Survival Analysis Tues 10/22 Class 17 Problem Set #4 due (Part 3b) Lecture notes: PUBH741-Part4.pdf; pp Logistic regression (Review RR, OR, logit function, model definition, interpretation of coefficients, hypothesis testing, likelihood ratio test, predicted values) Thurs 10/24 Class 18 Lecture notes: PUBH741-Part4.pdf; pp Logistic regression continued (modeling disease-exposure relationship, confounding, adjusted proportions, examples) Tues 10/29 Class 19 Review Problem Set #4 Article for midterm given out (TA lecture) Thurs 13/31 *** MIDTERM (in class) *** Tues 11/05 Class 20 Lecture notes: PUBH741-Part4.pdf; pp Survival analysis (Censored data, survivor function, hazard functions, Kaplan-Meier plot, log-rank test) Thurs 11/07 Class 21 Lecture notes: PUBH741-Part4.pdf; pp Survival analysis continued (Cox model, hazard ratio, proportional hazards assumption) Article: to be posted we will discuss in class

7 7 Part 5: Miscellaneous Topics Tues 11/12 Class 22 Problem Set #5 due (Part 4) Lecture notes: PUBH741-Part5.pdf; pp Cluster designs (intraclass correlation) Categorizing linear variables Article: Adams G, Gulliford MC, Obioha CU, Eldridge S, Chinn S, Campbell MJ. Patterns of intraclass correlation from primary care research to inform study design and analysis. J of Clin Epidemiol, 2004;57: Thurs 11/14 Class 23 Lecture Notes: PUBH741-Part5.pdf; pp Transformations of Y Transformations of X Tues 11/19 Class 24 Review Problem Set #5 Lecture notes: PUBH741-Part5.pdf; pp Article: Sun G, Shook TL, Kay GL. Inappropriate use of bivariable analysis to screen risk factors for use in multivariable analysis. J of Clin Epidemiol, 1996;49(8): Analysis strategies (univariable, bivariable) Thurs 11/21 Class 25 Lecture notes: PUBH741-Part5.pdf; pp PUBH741-Part5_Tables.pdf; pp Modeling strategies (modeling several X s, modeling one nominal X) Example tables Articles: Cummings P, Rivara FP. Reporting statistical information in medical journal articles. Arch Pediatr Adolesc Med, 2003;157: Von Elm E, et.al. STROBE statement: guidelines for reporting observational studies. Lancet, 2007;370: / Shulz K, et.al. CONSORT Statement: updated guidelines for reporting parallel group randomized trials. BMJ, 2010;340: Piaggio G, et.al. Reporting of noninferiority and equivalence randomized trials. JAMA, 2006;295(10):

8 8 Tues 11/26 Class 26 Finish discussion about strategies and tables; TA lecture/review *** FINAL EXAM project given out Thurs 11/28 Thanksgiving Tues 12/03 No Class (available for questions) Mon 12/09 EXAM DUE (by 8:00 a.m.)