PCM1: Intro to Epidemiology

=Objectives=

Define epidemiology and describe the importance of epidemiology concepts and methods to medicine and the evaluation of the medical literature.

 * epidemiology: the systematic study of the distribution of disease in populations
 * the study of the distribution of health-related events and their determinants (diseases,, conditions, symptoms, behaviros, risk factors, health attitudes, medical service contacts, etc,) in populations
 * a set of methods used to organize observations in populations to answer key research and clinical questions relevant to practice.


 * Use medical knowledge to make intelligent clinical decisions for individual patients
 * Use in interpreting evidence based medicine, following changes in standard of care
 * Public decision making, health policy, etc.

Describe the goals of epidemiology

 * 1) Describe the observed distribution of events in a population
 * Who?
 * What?
 * Where?
 * When?
 * 1) Develop interventions for decreasing risk and improving health; ie to do something.
 * 2) Develop and extend the knowledge base for the practice of medicine and public health
 * Evidence based medicine & public health issues

Describe the key components of measurement in epidemiology (numerator, denominator, estimation).
You need to turn observable information into data in order to analyze with the tools of epidemiology. Epidemiologists measure stuff.
 * numerator: number of cases occurred. used to describe
 * denominator: population or community or group of interest. defined by investigator.
 * prevalence:
 * incidence:


 * Observations -> Measurements
 * A good epidemiology evaluates the nature of the numerator, the nature of the denominator to determine the reliability of a study.


 * estimation: a measurement in a sample of the population/phenomenon that likely reflects the actual dynamics in the total population/sample


 * Statistical methods use mathematical tools for evaluating associations. Statistics need interpretation and do not provide a conclusion in themselves.  Statistics are the basis for inferences: rational interpretation of the data.
 * Values affect what we study, what we measure, and how we measure it.

Reproduce and describe the epidemiology world-view.

 * 1) The world is dynamic: stuff happens in the world. It happens in patterns and is not the result of randomness.
 * 2) Measure things systematically, accurately.
 * 1) Clinicians need to use the tools of epidemiology that combines science, experience, and intuition. The world view of an epidemiologist is that clinician needs to use these tools to augment the Art of Medicine.
 * 2) Clinical knowledge combines: intuition, experience, routines, and science/medical literature.


 * Evidence based medicine: practicing medicine on the basis of good evidence; evidence that has been subjected to critical scrutiny.

Describe the anatomy of a journal article.

 * descriptive studies: who, what, where. describe.  address questions that we can't get at otherwise.
 * case studies and case-series. collect rich information on a couple of people. example: case series collected by the CDC started research on HIV/AIDS.
 * ecological (correlation studies): group level information with limited applicability to individuals. becoming more interesting looking at social factors that we haven't traditionally considered.
 * cross-sectional::


 * analytics studies
 * case control studies
 * cohort studies
 * experimental studies (randomized clinical trial).


 * Journal article
 * Article title: catches your interest
 * Abstract-brief study of methods and results
 * Introduction-lays out the rational for the study and the questions.
 * Methods-details the study design. "where the meat is"
 * Results:
 * Discussion: