Epidemiology, Biostatistics, and Preventive Medicine

New York University - School of Medicine
New York, New York
Instructor(s): Koenig, Karen; Friedman-Jimenez, George
Subject area: Health / Medicine
Department: Environmental Medicine
Year taught: 1999
Level: Undergraduate Medical

Please note that the copyright for this syllabus is retained by the instructor.

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Textbooks
Elston, RC and Johnson, WD. Essentials of Biostatistics: 2nd ed. Philadelphia: F.A. Davis Co., 1994.

Fletcher, RH; Fletcher SW, and Wagner, EH. Clinical Epidemiology. 3rd ed. Baltimore: Williams & Wilkins, 1996.

Computer Text
Cody, RP and Just, SB. Understanding Biostatistics: A Computer-Based Tutorial. Units 1-5, 7. On IBM-type PCs in Computer Media Center, Main Reading Room in Library, and Coles.

Location of Classes
For lectures and review sessions, see following schedule. Conferences will be held in the
following rooms:

Group 1: Coles 301
Group 2: Coles 302
Group 3: Coles 303
Group 4: Coles 304
Group 5: Coles 305

Schedule

Date/Time	Class	Preparation
TH 9/2 2-3 pm	INTRODUCTORY LECTURE	Fletcher- Read Ch. 1
FRI 9/10 1-2:30 pm	CONFERENCE Probability Descriptive Statistics	Elston: Read Ch I, Ch 3 (pp 35-37, 49-58), Ch 4 (pp 65-75), Ch 5 (pp 91-96); Do Worksheet 1. Optional: Elston Problems Ch 3 (6-15), Ch 4 (1-9). Ch 5 (1-5); Cody: Units 1, 2, 7.
MON 9/13 10-11 am	LECTURE Distribution of the sample mean Alumni B	.
TH 9/16 2-3:30 pm	CONFERENCE Normal distribution Distribution of the sample mean Confidence intervals	Elston: Read Ch 5 (pp 100-107), Ch 6 (113-117, 119-130) Do Worksheet 2. Optional: Elston Problems Ch 5 (8-15), Ch 6 (1-3, 6-15); Cody: Unit 3.
TH 9/30 9:30-11 am	CONFERENCE Hypothsis Tests	Elston: Read Ch 7 (pJ 147,149-161); Do Worksheet 3. Optional: Elston Problems Ch 7 (1-7,12-14); Cody: Unit 4.
FRI 10/1 2-3:30 pm	CONFERENCE Comparing two means Comparing proportions	Elston: Read Ch 7 (pp 149-155), Ch 8 (pp 169-172, 175-184); Read Worksheet 4. Optional: Elston Problems Ch 7 (8-10,15), Ch 8 (2, 4-10, 13); Cody: Unit 5.
MON 10/4 10-1 1 am	LECTURE Intro to epidemiology and preventive medicine Alumni B	Fletcher: Read Ch 2.
FRJ 10/8 1-2:30 pm	CONFERENCE Epidemiologic measures	Fletcher: Read Ch 4, Ch 5 (pp 94-100, 105-109), Ch 6 (pp 130-132) Do Worksheet 5.
TUE 10/12 2-3:30 pm	CONFERENCE Clinical trials	Fletcher: Ch 6 (pp 116-123), Ch 7 (pp 149-157), Ch 9 (pp 200-205); Do Worksheet 6.
FRI 10/15 1-2:30 pm	CONFERENCE Cohort studies	Fletcher: Ch5 (ppl00-105), Ch 6 (pp 123-134), Ch 11 (pp 228-240); Do Worksheet 7.
TH 10/21 3-4:30 pm	CONFERENCE Case-control studies	Fletcher: Read Ch 10, Ch 11 (pp 241-247); Do Worksheet 8.
TH 10/28 10-11:30 am	REVIEW SESSION for Exam Alumni B	Do Worksheet 9 (Practice Problem Set); Bring your questions.
FRI 10/29 9-12pm	MIDTERM EXAMINATION Schwartz E	Review Cody: Units 1-5.7.
MON 11/1 10-11 am	LECTURE Diagnostic testing I Alumni B	Fletcher: Read Ch 3.
TH 11/4 9-10am	LECTURE Public health and clinical medicine Alumni B	Read Handout 10.
FRI 11/5 2-3:30pm	CONFERENCE Diagnostic testing II	Do Worksheet 11.
TH 11/11 2-3:30pm	CONFERENCE Diagnostic testing III	Do Worksheet 12.
MON 11/8 3:30-5pm (1) TUE 11/9 3-4:30pm (2) WED 11/10 3:30-5pm (3) TH 11/11 3:30-5pm (4) FRI 11/17 2-3:30pm (5)	CONFERENCE Literature searching Carlisle room (Library)	Fletcher: Read Ch 12, including Appendix 12.1
THU 11/18 2-3:30 pm	CONFERENCE Preventive medicine	Fletcher: Read Ch 8; Do Worksheet 13.
TH 12/2 1-2 pm	LECTURE Occupational and environmental medicine I Alumni B	Read Handout 14.
FRI 12/3 1-2 pm	LECTURE Occupational and environmental medicine II Schwartz F	.
TUE 12/7 2-3 pm	LECTURE Clinical toxicology Alumni B	Read Handout 15.
FRI 12/10 2-3:30 pm	CONFERENCE Occupational medicine	Do Worksheet 16 and slides
WED 12/15 11-12:30 pm	REVIEW SESSION for Exam Alumni A	Do Worksheet 17 (Practice Problem Set); Bring your questions
FRI 12/17 9-12pm	FINAL EXAMINATION Schwartz F	.

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Course Outline

I. INTRODUCTORY LECTURE

A. Course objectives and logistics
B. Introduction and course overview
C. Explanation of conference format

II. CONFERENCE: Descriptive Statistics and Probability

A. Descriptive statistics
1. Measures of central tendency: mean and median
2. Measures of variability: range, variance, standard deviation
B. Probability
1. Definitions of probability
2. Probability calculations
a. P(A or B)
(1) Mutually exclusive events
(2) Events which are not mutually exclusive
b. P(A and B)
(1) Independent events
(2) Events which are not independent
(3) Conditional probability
3. Binomial distribution
4. Sensitivity, specificity, predictive value as conditional probabilities

III. LECTURE: Distribution of the sample mean

IV. CONFERENCE: Normal Distribution, Populations, Samples, Confidence Intervals

A. Normal distribution
B. Populations and samples
C. Confidence intervals
1. Calculation
2. Interpretation

V. CONFERENCE: Hypothesis Tests

A. Null and alternative hypotheses
B. P-values
C. One-sided vs. two-sided tests
D. Significance level
E. Type I and type II errors
F. Statistical significance vs. medical importance

VI. CONFERENCE: Comparing Two Means, Comparing Proportions

A. Categorical vs. continuous variables
B. Choosing appropriate summary statistics
C. Choosing the appropriate statistical test
1. Two sample t-tests
2. Chi-square tests
D. Practice in interpreting output from statistical programs
E. Paired vs. unpaired comparisons

VII. LECTURE: Introduction to Epidemiology and Preventive Medicine

A. Role of Epidemiology in prevention
B. Role of Epidemiology in clinical diagnosis and treatment
C. Clinical and Public Health perspectives
D. Overview of Preventive Medicine
E. Introduction to basic principles of epidemiology

VIII. CONFERENCE: Epidemiologic Measures

A. Case discussions: Clinical questions with epidemiologic answers
B. Epidemiologic measures of disease occurrence
1. Risk
2. Prevalence
3. Incidence
C. Crude and adjusted rates
1. Age stratification and adjustment
D. Epidemiologic measures of effect and impact
1. Risk difference, relative risk, and attributable risk
2. Absolute and Relative Risk Reduction

IX. CONFERENCE: Clinical Trials

A. Case discussion motivating reading of a clinical trial report
B. Randomization
C. Blinding
D. Dropouts and non-compliers
E. Sample size and power
F. Survival analysis
1. Kaplan-Meier (univariate)
2. Proportional Hazards model (multivariate)
G. Interpreting results
H. Subgroup analyses

X. CONFERENCE: Cohort studies

A. Critical appraisal of a cohort study of etiology of disease
B. Basic principles of cohort studies
C. Bias: Types and likely directions
1. Confounding
a. Definition, qualitative examples
b. Methods to control confounding
2. Information Bias
a. Misclassification of exposure and disease
d. Nondifferential and differential misclassification
D. Principles of causal inference

XI. CONFERENCE: Case-Control Studies

A. Discussion of clinical case motivating critical reading of article
1. Formulating the clinical questions
B. Critical appraisal of a case-control study
1. Basic principles of Case Control studies
2. Odds Ratio as estimate of Relative Risk
3. General criteria for judging validity of a study
4. Guidelines for making causal inferences in epidemiologic studies of etiology
5. Bias: Types and likely directions.
a. Confounding (brief)
b. Selection Bias
c. Information Bias
(1) Interviewer bias, recall bias
(2) Misclassification bias

XII. REVIEW SESSION for Midterm Exam

A. Review practice problem set
B. Bring your questions

XIII. MIDTERM EXAMINATION

XIV. LECTURE: Diagnostic Testing I

A. Discussion of clinical cases motivating use of diagnostic tests
1. Probabilistic reasoning in clinical diagnosis: Formulating the main clinical diagnostic questions in simple cases.
B. Brief review of basic principles of diagnostic testing
1. Conditional probabilities
2. Pre-test and post-test probability of disease
3. Sensitivity, specificity, predictive values positive and using 2X2 table approach
C. ROC curves and Odds-Likelihood form of Bayes' Theorem.
D. Using likelihood ratios, pre- and post-test probabilities to aid in selection and interpretation of diagnostic tests.

XV. LECTURE: Public Health and Clinical Medicine

XVI. CONFERENCE: Diagnostic Testing II

A. Case discussion.
B. Application of Bayes' Theorem and likelihood ratios to clinical decision
making.
C. Communicating with patients about risks and diagnostic decisions.

XVII. CONFERENCE: Diagnostic Testing III

A. Case discussion and formulation of clinical questions.
B. Critical appraisal of study measuring operating characteristics of a diagnostic test
1. Comparison of test result with "gold standard" diagnosis
2. Potential biases in study of diagnostic test
C. Determining precision of estimates of operating characteristics.

XVIII. CONFERENCE: Literature Searching using Medline

XIX. CONFERENCE: Preventive Medicine

A. Role of the physician in clinical prevention and public health prevention
B. Levels of prevention with examples.
1. Primary, secondary, tertiary prevention
C. Medical Screening
1. Principles of screening for chronic diseases.
2. Examples of screening programs.
3. Simple application of Baye's Theorem to screening test
4. Discussion of the potential biases in studies of effectiveness of screening test (Lead time bias. Length bias, Compliance bias)
D. Measures of effectiveness of preventive interventions
E. Communication with patients of information about risk and prevention

XX. LECTURE: Occupational / Environmental Medicine: Prevention in Action, Part 1

A. Definitions & magnitude of the problem
B. Case presentations
C. Occupational & environmental medicine tools
1. Occupational sentinel health conditions
2. Clinical occupational toxicology
a. Dose-response relationships
b. Latency period and timing of exposure / disease
c. Routes of environmental exposure
d. Target organs
e. Biomarkers and biological monitoring
3. Brief screening occupational history
4. Information resources on occupational & environmental medicine for practicing clinicians

XXI. LECTURE: Occupational / Environmental Medicine: Prevention in Action, Part 2

XXII. LECTURE: Clinical Toxicology

A. Case presentations in acute toxicology
1. Vital signs and other simple clinical signs
2. Specific toxins
B. Examples of clinical utility of basic toxicologic principles
1. Toxicokinetics
2. Metabolic pathways
3. Receptor physiology and other mechanisms
4. Applications to diagnosis, treatment and antidotes

XXIII. CONFERENCE: Occupational Medicine

A. Case presentation: Asthma in a dental assistant
B. Diagnostic, treatment, prevention, public health issues
C. Critical appraisal of study of occupational asthma
D. Determination of occupational & environmental etiology of clinical cases.
1. Epidemiologic evidence
2. Toxicologic evidence
3. Clinical evidence
D. Public health issues arising from clinical cases
E. Medicolegal issues in occupational medicine
F. Communication about risks due to environmental agents

XXIV. REVIEW SESSION for Exam

A Review practice problem set
B. Bring your questions

XXV. FINAL EXAMINATION

Overall Course Objectives

Upon completion of this course, students will be able to demonstrate understanding of key basic principles of Epidemiology, Biostatistics, and Preventive Medicine. The student should be able to apply these basic principles to selected illustrative clinical and population level examples in Evidence Based Medicine and Preventive Medicine.

Biostatistics. The student should be able to:

• Summarize medical data.
• Perform simple probability calculations, including conditional probabilities.
• Compute and interpret confidence intervals
• Perform and interpret simple tests of statistical significance.

Epidemiology. The student should be able to:

• Define, calculate and interpret selected epidemiologic measures of incidence,
• prevalence and effect.
• Explain basic principles, study design, strengths and weaknesses of clinical trials, cohort studies, case-control studies, studies of diagnostic / screening tests and prevalence studies as related to clinical case examples.
• Describe and recognize major potential sources of bias in epidemiologic studies and suggest appropriate methods to control them.
• List and explain the criteria generally used to judge whether associations found in epidemiologic studies are likely to be causal, or not.
• Define, calculate, and interpret the operating characteristics of diagnostic / screening tests (sensitivity, specificity, predictive values, likelihood ratios).
• For several simple clinical scenarios, utilize evidence from medical literature and Bayes' Theorem to support selection and interpretation of diagnostic and screening tests, and optimal cutoff points.
• Use both 2x2 tables and Bayes' Theorem to calculate post-test probabilities of disease, for several illustrative clinical decision scenarios.

Preventive Medicine and Public Health. The student should be able to:

• Explain the 3 levels of prevention, with examples of each.
• Explain principles of medical screening.
• Explain examples of applications of public health principles in medicine.
• Describe each of a selected group of occupational / environmental sentinel health conditions and corresponding potential environmental etiologic agents.
• Explain the purpose and technique of taking a brief occupational history, and recognize important clinical clues that suggest possible occupational etiology.
• Explain clinically relevant concepts of environmental toxicology, as related to illustrative clinical cases.
• Interpret and describe the implications of measures of risk and disease risk factors for individual patients as well as populations at risk.

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This document was last modified on 07/24/2000 06:31:32 PM

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This resource was acquired by CEEM (Consortium for Environmental Education in Medicine), a program of Second Nature, under the auspices of a NIEHS grant to gather and disseminate environmental health educational resources over the internet in order to help medical and allied health sciences faculty identify, locate and use resources for incorporating environment and health perspectives into their curricula. CEEM has authorized the use of these materials on this website for archival purposes. Please note that the copyright for this material is retained by the instructor and/or contributing institution.