Epidemiology & Evidence Based Medicine Invited Lecturer: Tamar Kashibadze Tbilisi, 2022 The Aim of the Course This course will focus on providing students with a solid foundational understanding of the basic principles and methods of epidemiology and fundamental skills needed for organizing and analyzing raw data. As well as, to develop the skills necessary to answer public health questions using data, including: data acquisition, data analysis, data interpretation and the presentation of results. Day 1 – Learning Objectives “Introduction to Epidemiology” A Public Health Approach What Is Epidemiology? Key Concepts and Terms Epidemiology and Prevention Epidemiology and Clinical Practice The Epidemiologic Approach What is Health? “A state of complete physical, mental and social wellbeing and not merely the absence of disease or infirmity” - WHO And what is Public Health? “The science and art of preventing disease, prolonging life and promoting health, through the organized efforts of society” – Acheson, 1988, WHO How is it different to Medical Care? While Medicine is concerned with individual patients, Public Health is trying to improve the health of the population Medicine focuses on healing patients who are ill. Public Health focuses on preventing illness. A Public Health Approach Surveillance Risk Factor Identification Intervention Evaluation Implementation Public Health Core Sciences What is Epidemiology? “Study of the distribution and determinants of health-related states among specified populations and the application of that study to the control of health problems” - CDC The word epidemiology comes from the Greek words epi, meaning on or upon, demos, meaning people, and logos, meaning the study of Epidemiology Purposes in Public Health Practice • Discover the agent, host, and environmental factors that affect health • Determine the relative importance of causes of illness, disability, and death • Identify those segments of the population that have the greatest risk from specific causes of ill health • Evaluate the effectiveness of health programs and services in improving population health Solving Health Problems Step 1 Data collection Solving health problems Step 4 Action Action Step 1 - Surveillance; determine time, place, and person Step 2 Assessment Step 2 Inference Step 3 Hypothesis testing Step 3 Determine how and why Step 4 Intervention 9 Knowledge Check All of the following illustrate the purpose of epidemiology in public health, except A. identifying populations who are at risk for certain diseases. B. assessing the effectiveness of interventions. C. providing treatment for patients in clinical settings. D. determining the importance of causes of illness Epidemiology and Prevention A Different View • Population-based approach – a preventive measure widely applied to an entire population. • An alternative approach – targeted a high-risk group with the preventive measure. • Population-based approaches can be considered public health approaches, whereas high-risk approaches more often require a clinical action to identify the high-risk group to be targeted. • A combination of both approaches is ideal. Epidemiology Vs. Medicine • Epidemiology is critical not only to public health but also to clinical practice. • The practice of medicine is dependent on population data. Epidemiologic Approach • Descriptive Epidemiology – study of the distribution of disease (person, place and time) • Analytic Epidemiology – use of epidemiologic methods to explain disease occurrence or elucidate causal mechanisms Knowledge Check Epidemiologists use a model for studying infectious disease and its spread that involves the microbe that causes the disease, the organism that harbors the disease, and the external factors that cause or allow disease transmission. This is also known as A. host, vector, and transmission. B. transmission, host, and environment. C. host, agent, and environment. D. organism, transmission, and environment. Ignaz Semmelweis and Childbed Fever Ignaz Semmelweis was a Hungarian gynecologist who is known as a pioneer of antiseptic procedures. Semmelweis discovered that the incidence of puerperal fever could be drastically cut by the use of hand disinfection in obstetrical clinics. He is also described as the “savior of mothers” and “father of infection control”. Figure: Maternal mortality due to childbed fever, by type of care provider. Edward Jenner and Smallpox Edward Jenner, an English country doctor administers the world’s first vaccination as a preventive treatment for smallpox. He noticed that milkmaids who had contracted a disease called cowpox, which caused blistering on cow’s udders, did not catch smallpox. Unlike smallpox, which caused severe skin eruptions and dangerous fevers in humans, cowpox led to few ill symptoms in these women. On May 14, 1796, Jenner took fluid from a cowpox blister and scratched it into the skin of James Phipps, an eight-yearold boy. A single blister rose up on the spot, but James soon recovered. On July 1, Jenner inoculated the boy again, this time with smallpox matter, and no disease developed. The vaccine was a success. In 1980, the WHO certified that smallpox has been eradicated. John Snow and Cholera It was not until 1854 that the physician John Snow (1813-1858) made a major contribution to fighting cholera when he was able to demonstrate a link between cholera and the contaminated drinking water through his pioneering studies. By talking to local residents, Snow identified the source of the outbreak as the contaminated public water pump. “I hate definitions” – Benjamin Disraeli (1804 – 1881, British Prime Minister) Thanks for your attention!
