EPI 390 Lecture 5Outline of Last Lecture I. Modeling Epidemiologya. Covariance vs. ConfoundingII. Framing a Studya. Determining the Controlsb. Triagec. EfficiencyIII. Terminology in the Studya. Diseaseb. Syndromec. Illnessd. SicknessIV. Descriptive vs. Analytic EpidemiologyOutline of Current Lecture I. Review of defining EpidemiologyII. Roles of the EpidemiologistIII. Review of the “Magical Triad” of EpidemiologyIV. Continuation of Descriptive vs. Analytic EpidemiologyV. Lab Science vs. Field ScienceVI. Vectors for DiseaseVII. Quantifying DiseaseCurrent LectureI. Review of defining Epidemiologya. The study of the distribution of a disease or a physiological condition in human populations and of the factors that influence this distributionb. Purposes of epidemiology –i. Identifying the causes and risk factors for diseaseii. Determining the extent of disease in the communityiii. Studying the natural history and prognosis of diseaseiv. Evaluating preventive and therapeutic measuresv. Providing a foundation for public policyc. Etymology – Greek roots; epi = “upon” or “among”; demos = “people” or “district”; logos = “study” or “discourse”These notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.i. Translates to “The study of what is upon the people”II. Roles of the Epidemiologista. Epidemiologists measure disease frequency in populationsi. This involves: classifying and categorizing the disease1. Deciding what constitutes a case of disease in the study2. Finding a source for ascertaining the cases3. Defining the population at risk of disease4. Defining the period of time of risk for the disease5. Obtaining permission to study people6. Making measurement of disease frequency7. Relating cases to population and time at riskb. After determining the risk and frequency of disease, epidemiologists advise public health officials in proper action for treatment and preventive measuresIII. Review of the “Magical Triad” of Epidemiologya. Time - The time frame over which a study is done (a span of days or years)i. Does the event change over time or is it stable?ii. Seasonal changes are accounted foriii. Point estimate or multiple, increasing casesb. Place - The location of the study (i.e. a particular outbreak of E. coli infection in California)i. Geographic location; multiple locations or an individual outbreakii. Source of disease (i.e. air vs. water)c. Person – Those affected or at riski. Characterized by age, race, socio-economic status, education, behaviour, etc.IV. Continuation of Descriptive vs. Analytic EpidemiologyV. Lab Science vs. Field Sciencea. Difference between lab science and field science (field is anything not in the lab, staring down a microscope); can be prospective, retrospective, secondary data sets (could be entirely working on computer)VI. Vectors for Diseasea. Agents, Host factors, environmentVII. Quantifying Diseasea. Variability, heterogeneity, confounding variable, controls; how hard it is to control for thatb. Power – is sample size large/heterogeneous enough to get solid results from datac. Temporal component – prevalence vs. incidence (has time)d. Cross-sectional study – purely descriptive. For categorical datae. Answering questions on dichotomy or continuum. Continuum = better