Key Issues in Epidemiologic Research: An Overview. OBJECTIVES AND METHODS OR EPIDEMIOLOGIC RESEARCH. Fundamentals of Epidemiologic Research. Types of Epidemiologic Research. Design Options in Observational Studies. Typology of Observational Study Designs. Measures of Disease Frequency: Incidence. Other Measures of Disease Frequency. Measures of Association. Measures of Potential Impact and Summary of the Measures. VALIDITY OF EPIDEMIOLOGIC RESEARCH. Validity: General Considerations. Selection Bias. Information Bias. Confounding. Confounding Involving Several Risk Factors. PRINCIPLES AND PROCEDURES OF EPIDEMIOLOGIC ANALYSIS. Statistical Inferences About Effect Measures: Simple Analysis. Overview of Options for Control of Extraneous Factors. Stratified Analysis. Matching in Epidemiologic Studies. Interaction, Effect Modification, and Synergism. Modeling: Theoretical Considerations. Modeling: Analysis Strategy. Applications of Modeling with No Interaction. Applications of Logistic Regression with Interaction, Using Unconditional ML Estimation. Applications of Modeling: Conditional Likelihood Estimation. Appendices. Index.