Introduction to Epidemiology

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Date Developed: Unknown. Source: South Central Public Health Partnership. Presenter(s): Patricia Kissinger, PhD. Type: Online Course Video. Level: Introductory. Length: 420 minutes.


This ten-part lecture provides an in-depth orientation to the field of epidemiology. A short “Introduction” describes the discipline of epidemiology, including its relevant concepts and history. The next three sections cover the topic of surveillance. First, “Proportions, Rates and Ratios” presents differences between these three common measurements and describes specific examples, including differentiation between crude, specific, and adjusted (using both direct and indirect methods) values. Next, “Depictions of Epidemiologic Data” describes various tables, graphs, and charts that can be use to illustrate and examine trend data, also introducing the concepts of cohort, age, and period effects. “Descriptive Epidemiology and Outbreak Investigation” defines key terms and presents a step-by-step overview of conducting outbreak investigation. The middle three sections cover the concepts of precision and validity. “Measures of association” describes the calculation and application of relative risk, odds ratios, confidence intervals, and attributable risk. “Bias” describes types of systematic error that may exist in various studies; specifically information and selection bias, and describes the calculation of sensitivity, specificity, predictive values, and kappa statistics. “Confounding” describes the concept, assessment, and methodological considerations of confounding variables. The last three lectures further describe study design. “Experimental Studies” presents various experimental designs and related information, such as recruitment of subjects, blinding, intention to treat analysis, and types of error. “Observational Studies” defines cohort, case-control, and related study designs commonly used in analytic epidemiology. Finally, “Evaluation” describes impact assessment and measures of efficacy/effectiveness/efficiency, with particular focus on process evaluation and pre-test/post-test study design. Examples and a final quiz are used to reinforce learning.

Learning Objectives

Module 1: Intro

Module 2: Surveillance

Proportions, rates and ratios

• To discuss the difference between a rate, ratio and proportion.

• To discuss the difference between crude, specific and adjusted rates.

• To introduce the concept of confounding.

• To discuss the difference between incidence and prevalence.

Interpreting patterns of disease frequency.

• To discuss different methods of depicting data.

• To discuss the elements of a valid statistical association.

• To examine some descriptive data and discuss interpretations.

• To discuss the term “cohort effect”.

Descriptive epidemiology and outbreak investigation

• To discuss methods for conducting outbreak investigation.

• To discuss descriptive study designs:



Module 3: Precision and Validity

Measures of Association

• To state the hypothesis of a study.

• To calculate and interpret an odds ratio.

• To calculate and interpret a relative risk.

• To calculate and interpret a confidence interval.

• To discuss the difference between statistical and clinical significance.


• Discuss the terms precision and validity.

• To describe the types of bias that can occur.

• To discuss methods for preventing bias in study design.

• To discuss the kappa statistics.


• To discuss the terms: predictor, outcome, confounder and effect modifier.

• To an analysis to determine if confounding exists.

• To discuss the difference between confounder and effect modifier.

Module 4: Study Design

Experimental Designs

• To discuss the design of community trials.

• To discuss the design of clinical trials.

Observational Studies

• To discuss design issues of the cohort study.

• To discuss design issues of the case-control study.

• To compare and contrast the two designs.

• To discuss additional methods of minimizing confounding.


• To discuss the difference between impact and efficiency evaluation.

• To discuss the difference between process and outcome evaluation.

• To discuss formative and process evaluation.

• To describe examples of evaluation.

Special Instructions

Registration to the South Central Public Health Partnership is required. For new users it will take one weekday to receive an access email. If you are registered in TRAIN, login using that username and password. Click on "Course Offerings" and search for "Introduction to Epidemiology". [Note: videos may not be compatible with Macs]

This project is supported by the Health Resources and Services Administration (HRSA) of the U.S. Department of Health and Human Services (HHS) under grant number UE8MC25742; MCH Navigator for $180,000/year. This information or content and conclusions are those of the author and should not be construed as the official position or policy of, nor should any endorsements be inferred by HRSA, HHS or the U.S. Government.