EPIDEMIOLOGY GRADUATE PROGRAM

FREQUENTLY ASKED QUESTIONS ABOUT THE

QUALIFYING EXAM

The 2008 Qualifying Examination will be held on Monday and Tuesday, June 2 & 3, 2008.

The “Who, What, When, & Where” for the Qualifying Exam

Who needs to take the qualifying exam?

• EPI major MS students

• EPI major PhD students

• EPI minor PhD students

What is the qualifying exam?

• The qualifying exam or QE is a two-day written in-class exam consisting of 6 questions intended to assess how well the student comprehends and has integrated both the Epidemiology and Biostatistics core course competencies.  The exam lasts for 4 hours on each of the two days (8 hours total).

•  Each student must achieve an overall score at least 75% in order to pass the exam. 

• The exam typically begins at 9 am and ends at 1 pm each day.  Any exceptions to this will be announced by email before the exam takes place. 

• Students are encouraged to form study groups to prepare for the exam, but should practice on their own as well.

• Each student is allowed two pages of notes (front and back), which include what each student thinks he/she will need to answer questions.  This may include specific formulas, concepts, definitions, whatever the student would like to include.  Each student is allowed the use of an English-language dictionary.

When do students need to take the exam?

• Students may take the exam after successful completion of the four core courses: EPI/CPH 573A and 573B and EPI/CPH 576A and 576B. 

• The exam will be offered in the summer before classes start.  Exact dates will be announced in the spring semester preceding the exam. 

• Students planning to take the qualifying exam should contact the Curriculum Coordinator, Sara Brinson, by the end of the spring semester prior to administration of the exam in order to get on a mailing list so that any information or changes in scheduling will be received in a timely fashion.   

Where will the exam take place?

• The location of the QE is dependent on the number of students taking the exam.  This will be announced by email to students who have signed up with the Curriculum Coordinator in the Office of Academic Affairs.  Location information should be available by the beginning of July.

Grading of the Exam

• There will be two blinded graders for each question in order to avoid interrater discrepancies.   If necessary, a third grader may also evaluate answers.

• The graders report to the co-chairs of the qualifying exam committee.  The results will be reviewed by the co-chairs and grades of pass/fail awarded. 

• Results of the QE should be available to students within three weeks.

• Students may appeal any final grade using the Graduate College procedures if so desired as outlined in the Graduate College handbook.

• Students are encouraged to meet with graders in order to discuss strengths and weaknesses of student responses to the QE questions.

Preparing for the QE

• The best way to prepare for the QE is to study old exams from the core courses.  The same instructors who developed those exams write the QE questions, and the goal of the QE is to test the knowledge covered in the core courses.  Thus, QE questions strongly resemble exam questions from the core courses.  An effort is made to include a variety of questions including (a) theoretical, essay-style responses, (b) hand calculations, and (c) interpreting computer outputs.

• Study groups can be very helpful; however, students are advised to study the competencies and/or solve practice problems independently, and then use group study work to detect their mistakes and to consolidate their learning.  Study groups where members “divide up” the competencies and prepare answers to be distributed can be counterproductive, as the best learning occurs from engaging with the material directly.

• Building the formula sheets can be a very useful way to review important principles.  It can be very helpful to compare sheets with other students for coverage, and to consult notes and guides from the core classes.

• Following are the competencies that will be covered by the QE questions.

Epidemiology Competencies

(Expected learning outcomes from EPI/CPH 573A and EPI/CPH 573B)

By the end of the first year of courses, we expect the student to be able to:

• Identify criteria for the assessment of causation, i.e. how to judge if an association is causal

• Generate hypotheses and determine appropriate study design for the hypothesis

• Calculate and interpret measures of frequency (rates, ratios, crude versus adjusted, attack rates, incidence, prevalence, case-fatality)

• Calculate and interpret measures of effect (relative risk, odds ratio, attributable risk, AR% and PAR%)

• Describe advantages, disadvantages, elements of study design, and appropriate effect measures for various epidemiological study designs

• Evaluate appropriateness of screening and calculate measures of validity of tests (sensitivity, specificity, positive and negative predictive values)

• Identify potential sources of bias and their probable effect on the validity of a study or study findings (selection bias, information bias, confounding, differential vs. nondifferential misclassification)

• Describe how to detect and deal with confounding and effect modification (including stratification, randomization, matching, multivariate approaches)

• Describe effect of chance (sample size, power) on study design and interpretations (confidence intervals, p-values)

• Critique an epidemiological paper

Biostatistics Competencies

Expected learning outcomes from EPI/CPH 576A and EPI/CPH 576B

For testing purposes, biostatistics competencies rest on two major themes:

• If faced with data, can the student figure out how to analyze them?

• If faced with results from data analysis, can the student demonstrate understanding of what they mean and interpret them in the appropriate scientific context?

Testing objectives for PHL 576A and 576B:

• Is the student able to recognize the type of data and to select the appropriate analytical method, using descriptive statistics (numeric and graphical) as necessary in the decision-making process?

• Does the student understand the assumptions necessary for a given statistical procedure?  Is the student able to determine if the assumptions are met for a given data set, relying on appropriate descriptive statistics as necessary?

• Does the student really know and understand the hypothesis being tested with the various statistical procedures?

• Does the student understand the relationship between error types, power, and sample sizes and the practical ways to adjust them?

Specific areas of knowledge:

Levels of data measurement (nominal, ordinal, discrete/continuous)

Measures of central tendency, skewness

Standard deviation, variance, degrees of freedom, standard error

Standard normal, binomial distributions

Hypothesis testing, confidence intervals

z-test, 1 and 2 sample t-tests (independent and related)

ANOVA

Relative Risk, Odds Ratio

tests of proportions

Contingency tables, non-parametric statistics

Correlation (Pearson and Spearman)

Indicator variables, interaction terms

Linear regression models and diagnostics

Analysis of covariance

Logistic regression models, diagnostics, goodness-of-fit

Stratified analysis

Survival curves, estimation, testing

Cox proportional hazards model

Poisson regression

Sample size and power estimation for comparing means and proportions

Sample size and power estimation for case-control (unmatched and matched) and cohort studies

Things to remember on the day of the exam

• Bring your formula sheets. 

• Bring a hand calculator

• Bring ample food and water.

• Bring extra pens and pencils.

• Start each answer on a fresh page and write only on one side of each page. Each question may have different graders, and by having questions on separate pages, it is much easier to copy and distribute exams to graders.  This results in a faster turn-around time for grades back to students.

• You receive three questions each day, and you are free to answer them in any order desired.

• Read each question in its entirety carefully before beginning to answer it.  Sometimes useful information is included in the question, reducing the amount of calculation required.  Occasionally in the past, students have spent considerable time deriving information that is already provided.