รวมเล่ม_PowerPoint_ว.ระบาดวิทยาฯ 2565 (Wanpen)

Course Description 4172107 Epidemiology and Biostatistics ระบาดวทิ ยาและชีวสถติ ิ Credits 2(2-0-4) Concept, Principle and Scope of Epidemiology, Natural of Diseases and Distribution, Epidemiology Study Designs, Biostatistics, Health Index, Disease Surveillances and investigation, Disease Prevention and Control, Epidemiology information technology

Course objectives At the end of the course learners should be able to 1 Explain concepts, principles, and scope of epidemiology 2 Describe the nature of disease and distribution for non-infectious/chronic and infectious diseases 3 Able to analyze and interpret the biostatistics data

Course objeCtives…continue 4 Able to calculate health index in public health 5 Explain the application of the epidemiological study designs 6 Explain concept of disease investigations and surveillance 7 Specify guidelines or principles of disease prevention and control 8 Explain the use of epidemiological information technology

Course details Chapter 1 Chapter 2 Chapter 4 Concept Principle Natural of Health Index and Scope of Diseases and Epidemiology Distribution 8 Chapters 2(2-0-4) Chapter 3 Biostatistics

Course details Chapter 5 Epidemiology Study Designs Chapter 6 Disease Surveillances and Investigation Chapter 7 Disease Prevention and Control Chapter 8 Epidemiology Information Technology

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Chapter objectives At the end of the chapter learners should be able to 1 Explain the definition of epidemiology 2 Explain the concepts or principles of epidemiology 3 Summarize the historical evolution of epidemiology 4 Specify the scope of epidemiology

The word “epidemiology” comes from the Greek words: epi meaning on or upon, demos meaning people, logos meaning the study of, Source: Centers for Disease Control and Prevention (CDC), 2012, P.14

Definition …1… Epidemiology is a branch of medicine that is concerned with the occurrence, distribution, and control of epidemic diseases. Source: https://www.collinsdictionary.com/dictionary/english/epidemiology, January 2022

Definition …2… Epidemiology is the study of the distribution and determinants of infectious or chronic diseases. เครอื ข่ายระหว่างประเทศดา้ นนโยบายทางระบาดวิทยา The International Network for Epidemiology in Policy (INEP) is a consortium of 24 epidemiological societies based around the globe  Source: https://www.apha.org/apha-communities/member-sections/epidemiology, 22 January, 2022

Definition …3… “The study of the distribution and determinants of health- related states or events in specified populations and the application of this study to control of health problems” (Porta, 2008; Celentano & Szklo, 2019) study distribution determinants health-related states or events specified populations application control of health problems

the important concepts/principles : Study (การศึกษา)  The foundation of epidemiology is a scientific of inquiry.  Epidemiology uses a systematic and unbiased approach to the collection, analysis, and interpretation of data.  Basic epidemiologic methods are careful observation and use of valid comparison groups to assess whether what was observed.  Epidemiology derived methods from other scientific fields such as Biostatistics and Informatics, with Biologic, Economic, Social, and Behavioral sciences. Source: Centers for Disease Control and Prevention (CDC), 2012

the important concepts/principles : Distribution (การกระจาย) Epidemiology is concerned with the frequency and pattern of health events in a population:  Frequency refers not only to the number of health events, but also to the relationship of that number to the size of the population.  Pattern refers to the occurrence of health- related events by time, place, and person. Source: Centers for Disease Control and Prevention (CDC), 2012

the important concepts/principles : : Determinants (ปัจจยั ก่อโรค) Determinants or potential risk factors are the causes and other factors that influence the occurrence of disease and other health-related events. Source: Centers for Disease Control and Prevention (CDC), 2012

the important concepts/principles : Health-related states (ภาวะสุขภาพ) or Events (การเกดิ โรค)  Health-related states or events may be seen as anything that affects the well-being of a opulation.  Many epidemiologists still use the term “disease”  communicable diseases,  injuries,  non-communicable infectious  birth defects, diseases,  maternal-child health,  chronic diseases,  occupational health, and  environmental health Source: Centers for Disease Control and Prevention (CDC), 2012

the important principles : Specified populations (ประชากรทรี่ ะบุ) People in a community or population  Clinician’s “patient” is the individual  The epidemiologist’s “patient” is the community. Source: Centers for Disease Control and Prevention (CDC), 2012

the important principles : Application (การประยกุ ต์) Epidemiology is not just “the study of” health in a population; it also involves applying the knowledge gained by the studies to community-based practice. Source: Centers for Disease Control and Prevention (CDC), 2012



Historical Evolution of Epidemiology  Epidemiologic thinking has been traced from Hippocrates through John Graunt, William Farr, and John Snow.

Historical Evolution of Epidemiology Hippocrates: Circa 400 B.C. (ประมาณ 400 ปีกอ่ นครสิ ตกาล)  Hippocrates proposed that disease occurrence from a rational rather than a supernatural viewpoint, “on airs, waters, and places”  Hippocrates believed that environmental and host factors such as behaviors might influence the development of disease. Source: Centers for Disease Control and Prevention (CDC), 2012

Historical Evolution of Epidemiology John Graunt: 1662  John Graunt, a London haberdasher and councilman (นกั ธุรกิจและสมาชิกสภาในลอนดอน) published the first landmark analysis of mortality data including quantify patterns of birth, death, and disease occurrence, high infant mortality, noting disparities between males and females (สงั เกตความแตกตา่ งระหวา่ งชาย และหญิง), urban/rural differences, and seasonal variations. Source: Centers for Disease Control and Prevention (CDC), 2012

Historical Evolution of Epidemiology William Farr : 1800  William Farr considered the father of modern vital statistics and surveillance (บดิ าแหง่ การเฝา้ ระวงั และสถิติชีพสมยั ใหม่)  He built systematically collecting and analyzing Britain’s mortality statistics, developed many of the basic practices used today in vital statistics and disease classification.  He did collecting vital statistics, assembling and evaluating those data, and reporting to responsible health authorities and the general public. Source: Centers for Disease Control and Prevention (CDC), 2012

Historical Evolution of Epidemiology John Snow: 1854  John Snow, an anesthesiologist and considered the father of field epidemiology (บิดาแหง่ ระบาดวิทยาภาคสนาม) conducted studies of cholera outbreaks both to discover the cause of disease and to prevent its recurrence.  His famous studies emerged when an epidemic of cholera erupted in the Golden Square of London by determining where in this area persons with cholera lived and worked. Then marked each residence on a map of the area showing the geographic distribution of cases.  Today his map is called a spot map.  His work demonstrated the sequence from descriptive epidemiology to hypothesis generation to hypothesis testing (analytic epidemiology) to application. Source: Centers for Disease Control and Prevention (CDC), 2012

Historical Evolution of Epidemiology

Historical Evolution of Epidemiology 19th and 20th centuries  In the mid-and late-1800s, epidemiological methods began to be applied in disease occurrence, and most of the investigators focused on acute infectious diseases.  In the 1930s and 1940s, epidemiologists extended their methods to noninfectious diseases.  In the 1980s, epidemiology was extended to the studies of injuries and violence. Source: Centers for Disease Control and Prevention (CDC), 2012

Historical Evolution of Epidemiology 19th and 20th centuries  In the 1990s, epidemiology was extended to the studies of the related fields of molecular and genetic epidemiology, infectious agents emerged (Ebola virus, Human Immunodeficiency Virus (HIV)/ Acquired Immunodeficiency Syndrome (AIDS) Severe Acute Respiratory Syndrome (SARS), Avian influenza.  Beginning in the 1990s, after the terrorist attacks of September 11, 2001, epidemiologists have had to consider not only natural transmission of infectious organisms but also deliberate spread through biologic warfare and bioterrorism.  In December 2019, epidemiologists have to be concerned about the pandemic of COVID-19, an infectious respiratory illness caused by the severe acute respiratory syndrome–coronavirus 2 (SARS-CoV2). Source: Centers for Disease Control and Prevention (CDC), 2012; Dhar Chowdhury & Oommen, 2020

What are the specific objectivesobjectives of epidemiology of epidemiology? to identify the etiology or cause, of a disease and its relevant risk factors (factors that increase a person's risk for a disease) to determine the extent of disease found in the community. to study the natural history and prognosis of disease. Source: Celentano & Szklo, 2019

What are the specific objectivesobjectives of epidemiology of epidemiology? To evaluate both existing and newly developed preventive and therapeutic measures and modes of health care delivery. To provide the foundation for developing public policy relating to environmental problems, genetic issues, and other social and behavioral considerations regarding disease prevention and health promotion. Source: Celentano & Szklo, 2019

scope of epidemiology Geographic pathology No.1 พยาธิวทิ ยาทางภมู ศิ าสตร์ Clinical epidemiology No.2 ระบาดวทิ ยาคลนิ ิก Identification of agents of disease No.3 การระบสุ าเหตขุ องโรค No.4 Statistical epidemiology ระบาดวิทยาทางสถิติ No.5 Field survey for specific purpose การสารวจภาคสนามเพ่ือวตั ถปุ ระสงคเ์ ฉพาะ Source: Department of epidemiology, Faculty of public health, Mahidol university, 2012

scope of epidemiology No.6 Incidence study (Longitudinal study) การศกึ ษาอบุ ตั ิการณ์ (การศกึ ษาระยะยาว) No.7 Experimental epidemiology ระบาดวิทยาเชิงทดลอง Tracing reservoirs and source of infection No.8 ตดิ ตามแหลง่ กกั เก็บและแหลง่ ท่ีมาของการตดิ เชือ้ No.9 Administration control of disease Source: Department of epidemiology, Faculty of public health, Mahidol university, 2012

Advantage of Epidemiology Epidemiology and the information generated by epidemiologic methods have been used in many ways.  Assessing the community’s health by assess the health of a population or community, relevant sources of data which must be identified and analyzed by person, place, and time • What are the actual and potential health problems in the community? • Where are they occurring? • Which populations are at increased risk? • Which problems have declined over time? • Which ones are increasing or have the potential to increase? • How do these patterns relate to the level and distribution of public health services available? Source: Centers for Disease Control and Prevention (CDC), 2012

Advantage of Epidemiology  Making individual decisions Many individuals may not realize that they use epidemiologic information to make daily decisions affecting their health.  Completing the clinical picture When investigating a disease outbreak, epidemiologists rely on health-care providers and laboratorians to establish the proper diagnosis of individual patients. But epidemiologists also contribute to physicians’ understanding of the clinical picture and natural history of disease.  Searching for causes Much epidemiologic research is devoted to searching for causal factors that influence one’s risk of disease. Epidemiology often provides enough information to support effective action. Source: Centers for Disease Control and Prevention (CDC), 2012

summary  Epidemiology is the study of the disease distribution in populations and the factors that influence or source of this distribution.  The important concepts/principles of epidemiology are study, distribution, determinants, health-related states or events, specified populations, and application.  Epidemiology’s roots are nearly 2500 years old, Since Hippocrates through John Graunt, William Farr, John Snow, and current epidemiologist, all of those that provide a lot of valuable knowledge for implementation.

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The contents of this chapter 1 Epidemiologic triad The nature of a disease and 2 distribution in a population (man)

Epidemiologic triad (ปัจจัยสามทางวิทยาการระบาด) Agent • ปัจจยั ก่อโรค Host • มนษุ ย์ Environment • ส่ิงแวดลอ้ ม

Epidemiologic triad (ปัจจัยสามทางวทิ ยาการระบาด) Agent (ปัจจยั ก่อโรค ) Agent originally referred to an infectious microorganism or ➢ pathogen: a virus, bacterium, ➢ parasite, or other microbe. ➢ ➢ The concept of agent has been broadened to include chemical and physical causes of disease or injury. PICTURE from: https://www.pixtastock.com/illustration/50493745

Epidemiologic triad (ปัจจยั สามทางวิทยาการระบาด) Behaviors Beliefs Susceptibility Attitudes Personal habits Age Sexual practices, Culture Sex Sexual practices Genetic Host Nutritional status Hygiene Immunologic status Anatomic structure Psychological aspect Underlying disease Presence of or medications, Host refers to the human who can get the disease.

Epidemiologic triad (ปัจจยั สามทางวทิ ยาการระบาด) Environment Geography Physical factor Season Biologic factor ✓ Human population ✓ Food plants ✓ Vectors Chemical factor Socioeconomic factor PM 2.5 CO2 Environment refers to extrinsic factors that affect the agent and the opportunity for exposure.

Interaction of the Host, Agent, and Environment

Interaction of the Host, Agent, and Environment Prepathogenesis Period Pathogenesis Period

Interaction of the Host, Agent, and Environment Pathogenesis Period

The nature of a disease 1 in a population (man)

➢ It occurs in some members of the population. ➢ Risk factors may not be distributed randomly in the population.

•Natural history of disease refers to the progression of a disease process in an individual over time, in the absence of treatment. Source: Centers for Disease Control and Prevention. Principles of epidemiology, 3rd ed. Atlanta: U.S. Department of Health and Human Services; 2012, p71.

Natural of disease timeline 12 3 4 Pathologic Usual Time Stage of Changes of Diagnosis Recovery, Disability, Exposure Chronic or Death Onset of symptoms Stage of Stage of Stage of Susceptibility Subclinical Disease Clinical Disease Source: Centers for Disease Control and Prevention. Principles of epidemiology, 3rd ed. Atlanta: U.S. Department of Health and Human Services; 2012, p71.

Natural of disease timeline Usual Time of Diagnosis Pathologic Exposure Changes Source: Centers for Disease Control and Prevention. Principles of epidemiology, 3rd ed. Atlanta: U.S. Department of Health and Human Services; 2012, p71.