Statistical Reasoning II 



 
 November 22, 2009

 
Course Syllabus


 

Course Description

Provides a broad overview of biostatistical methods and concepts used in the public health sciences, emphasizing interpretation and concepts rather than calculations or mathematical details. Develops ability to read the scientific literature to critically evaluate study designs and methods of data analysis. Introduces basic concepts of statistical inference, including hypothesis testing, p-values, and confidence intervals. Topics include comparisons of means and proportions; the normal distribution; regression and correlation; confounding; concepts of study design, including randomization, sample size, and power considerations; logistic regression; and an overview of some methods in survival analysis. Draws examples of the use and abuse of statistical methods from the current biomedical literature.


Course Objectives

Upon completion of this course, you will be able to:

  • Recognize different study designs and understand the pros and cons of each
  • Learn methods for randomly assigning subjects to two groups
  • Understand the concepts of confounding and statistical interaction; know how to recognize each
  • Explain the relationship between power and sample size; use Stata to perform sample size calculations
  • Create a scatterplot to visually assess the nature of an association between two continuous variables
  • Interpret the calculated values of the correlation coefficient and the coefficient of determination, and understand the relationship between these two measures of association
  • Perform a simple linear regression using Stata and use the results to assess the magnitude and significance of the relationship between a continuous outcome variable and a continuous predictor variable and for predicting values of the outcome variable
  • Understand why multiple regression techniques allow for the analysis of the relationship between an outcome and a predictor in the presence of confounding variables
  • Perform a multiple linear regression using Stata and use the results to assess the magnitude and significance of the relationship between a continuous outcome variable and multiple continuous and categorical predictor variables and for predicting values of the outcome variable
  • Perform a multiple logistic regression using Stata and use the results to assess the magnitude and significance of the relationship between a dichotomous outcome variable and multiple continuous and categorical predictor variables
  • Interpret the results from a proportional hazards regression model

Course Topics

  • Issues in study design
  • Correlation and simple linear regression
  • Multiple linear regression
  • Multiple logistic regression
  • Introduction to censored survival data
  • The Kaplan-Meier method for constructing survival curves
  • Multivaritate survival analysis via Cox proportional hazards regression

Course Format

The content of this course is divided into four separate modules. All the required course work can be accessed from the Course Modules page. The lecture sections are presented sequentially and should be completed in that order. Each of these sections combines audio presentation and slides—just like attending lectures in class. You may return to any previous section at any point and review its contents at your convenience. In each lecture section, you will find a listing of the section objectives, links to the lecture materials, a listing of reading assignments, and links to Web resources.


Course Materials

There is no textbook for this course.

Reading Material

The recommended reading material for the course will be in the eReserves system. If you are prompted for a password, please enter 140612sph. 

Students are also required to have access to "Small Stata," a version of Stata that is less powerful (in terms of the amount of data it can store and process, not in terms of functionality) than regular "Intercooled Stata" and costs significantly less ($48 for a one year license). Small Stata carries a one-year users license. However, if you intend to further your study of statistics beyond this course, you may wish to purchase a copy of Intercooled Stata 10. With the discount for graduate students, this costs $95 for a one year license, or $155 for a perpetual license. These can be ordered directly via Stata (http://www.stata.com/order/new/edu/gradplans/gp-direct.html). In order to get the academic discount, you will need to indicate that you are a student at Hopkins and you will need to provide your student ID number.

Other useful, but optional, references include the following:

  • Freedman, D., Pisani, R., Purves, R. Statistics
  • Moore, D., McCabe, G. Introduction to the Practice of Statistics
  • Altman, D.G. (1991). Practical Statistics for Medical Research. London: Chapman and Hall

You may purchase these textbooks from Matthews Medical Book Center or Amazon.com. Stata may be purchased directly from Stata Corporation


Course Assignments and Grading Policy

50% of grade: You are required to complete three homework assignments. These exercises will encompass the interpretation of concepts covered in class and give some practice with using Stata for very common computations. These exercises must be submitted to the Drop Box.

20% of grade: You must complete the mid-term exam. This will be administered online, and will be available for a limited time period.

30% of grade: You must complete the final exam. This is a closed-book, proctored exam. You will receive further information and details about the final exam and identifying a proctor from your professor.

  • Exam step 1: Select a professional person as your proctor—a work supervisor, for example, or a librarian, or a member of clergy, etc., following the specified DED proctored exam guidelines. Confirm your proctor’s availability to distribute the exam on the approved testing dates, which are indicated on the course schedule next to the exam listing. Then complete and submit the proctor selection form on the guidelines page. You must submit this form no later than the due date indicated on the course schedule.
  • Exam step 2: The exam packet will be emailed to your proctor shortly prior to the date of the exam.
  • Exam step 3: Take the exam on your selected date, following the specific instructions included in the exam packet for taking and returning the exam. Set aside roughly an hour-and-a-half (1.5 hours) to take this exam. This is a closed-book exam with short answer and multiple choice questions. Bring a pen or pencil.

Evaluation

Lecture and instructor evaluation: Feedback from students each year has greatly enhanced the course. An online evaluation form is available during the last week of the course. In addition, during the LiveTalk session of the last week, we will discuss what was helpful or not helpful and how the course could be improved. By having a discussion, suggestions can be clarified and enhanced. These discussions have proved much more helpful than written evaluations.

 

Contact Information

 Faculty Contact

John McGready
Johns Hopkins Bloomberg School of Public Health
Department of Biostatistics
615 North Wolfe Street, Room E3527
Baltimore MD 21205
(410) 614-9405
(410) 955-0958 (Fax)

Teaching Assistants 

Yaping Wang
Shanshan Li
George Wu
Andrew Mirelman

John Hopkins Bloomberg School of Public Health
Department of Biostatistics
615 North Wolfe Street, Room E3005
Baltimore, MD 21205

Homework assignments should be submitted via the Drop Box.


Help

Concerns
Contact
Concerns about course topics and assignments
Technical concerns about the functionality and operation of course Web pages (before emailing, please make sure that you can replicate the problem)
  • DEHelp, the central help system for all tech support inquiries related to DED courses

Technical help on weekends
  • JHSPH User Support: 410-955-3781
Concerns about your Internet connection
  • Your Internet service provider (e.g., AT&T, Erols, etc.)
Concerns about your personal software
  • Your software vendor


Schedule

The Course Schedule outlines all the important course dates and deadlines but does not contain links to access course material. The Course Content page (password-protected) is set up like the schedule page but provides access to course materials.


Ethical Conduct

The academic ethics code, as discussed in the Policy and Procedure Memorandum for Students, March 31, 2002, will be adhered to in this class.


Disability Support Services

If you are a student with a documented disability who requires an academic accommodation, please contact Betty H. Addison in the Office of Career Services and Disability Support: dss@jhsph.edu, 410-955-3034, or Room E-1140.


 

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Copyright to this collective work of materials is owned by The Johns Hopkins University.
Copyright to individual contributions may be retained by contributing authors.