Lecture 1: Introduction to Epidemiology - 2nd Semester 2022

Lecture 1 Introduction to Epidemiology Nimer Aldaghameen Department of Nursing Modern University College, Palestine 2nd Semester, 2022  What is Epidemiology? The word epidemiology comes from the Greek words Epi, meaning on or upon, Demo...

Lecture 1 Introduction to Epidemiology Nimer Aldaghameen Department of Nursing Modern University College, Palestine 2nd Semester, 2022  What is Epidemiology? The word epidemiology comes from the Greek words Epi, meaning on or upon, Demos, meaning people, and logos, meaning the study of.  What is Epidemiology? The study of the distribution (frequency, pattern) and determinants (causes, risk factors) of health-related states or events in specified populations, and the application of this study to control of health problems. ‫ علم األوبئة هو دراسة توزيع ومحددات الحاالت أو األحداث المتعلقة بالصحة في‬.‫ وتطبيق هذه الدراسة للسيطرة على المشاكل الصحية‬،‫مجموعات سكانية محددة‬  What is Epidemiology? ▪ Epidemiologists study sick people. ▪ Epidemiologists study healthy people. ▪ To determine the crucial difference between those who get the disease and those who are spared. ‫لتحديد االختالف‬ ‫الجوهري بين أولئك الذين يصابون بالمرض والذين تم إنقاذهم‬ ▪ Epidemiologists study exposed people. ▪ Epidemiologists study non-exposed people. ▪ To determine the crucial effect of the exposure.  Uses of Epidemiology ▪ To determine, describe, and report on the natural course of disease, disability, injury, and death. ▪ To aid in the planning and development of health services and programs. ▪ To provide administrative and planning data. ▪ To study the cause (or etiology) of disease(s), or conditions, disorders, disabilities, etc. ▪ To determine the primary agent responsible or ascertain causative factors. ▪ To determine the characteristics of the agent or causative factors. ▪ To determine the mode of transmission. ▪ To determine contributing factors. ▪ To identify and determine geographic patterns.  Purpose of Epidemiology ▪ To provide a basis for developing disease control and prevention measures for groups at risk. ▪ Developing measures to prevent or control disease.  Types of Epidemiology: ▪ Descriptive epidemiology: examining the distribution of disease in a population, and observing the basic features of its distribution. ▪ Analytic epidemiology: investigating a hypothesis about the cause of disease by studying how exposures relate to disease.  Descriptive epidemiology is antecedent to analytical epidemiology Analytical epidemiology studies require information to... ▪ Know where to look. ▪ Know what to control for. ▪ Develop viable hypotheses. Three essentials characteristics of disease that we look for in descriptive studies are... ✓Person. ✓Place. ✓Time. Person ✓Age, gender, ethnic group. ✓Genetic predisposition. ✓Concurrent disease. ✓Diet, physical activity, smoking. ✓Risk taking behavior. ✓SES (Socioeconomic Status), education, occupation. Geographic Place ✓Presence of agents or vectors. ✓Climate. ✓Geology. ✓Population density. ✓Economic development. ✓Nutritional practices. ✓Medical practices. Time ✓Calendar time. ✓Time since an event. ✓Physiologic cycles. ✓Age (time since birth). ✓Seasonality. ✓Temporal trends. The Epidemiologic Triangle: three characteristics that are examined to study the cause(s) for disease in analytic epidemiology Agent ▪ Agent. ▪ Host. ▪ Environment. Host Environment  The Epidemiologic Triangle Agents: originally referred to an infectious microorganism or pathogen: a virus, bacterium, parasite, A variety of factors influence whether exposure to an organism will result in disease, including the organism’s pathogenicity (ability to cause disease) and dose. Agent Biological (Bacterial, Viruses, Parasites….) Physical (Trauma, Radiation. Burns, Electric injuries..) Chemical (Alcohol, Poison, Smoke….) Influence the chance for disease or its severity Environment Host  The Epidemiologic Triangle Host: refers to the human who can get the disease. Agent Personal traits. Behaviors. Genetic predisposition. Immunologic factors. Environment Host  The Epidemiologic Triangle Environment: refers to extrinsic factors that affect the agent and the opportunity for exposure. Agent External conditions Physical/biological/social Contribute to the disease process Host Environment