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Litman emil 100427053_majorindividualassignment



Final Assignment for Epidemiology

Final Assignment for Epidemiology



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  • Hi! My name is Emil Litman and I really enjoyed being a part of this course. For my Major Individual Project, I have decided to create a PowerPoint presentation as I personally found that it would be more organized and still give the same overall effect. So sit back and I hope you can enjoy the knowledge which I have learnt as well!
  • Prior to starting this course, Dr. Emma Bartfay asked us two questions: Are you clear on the course expectation?  If not, please specify. And Have you encountered any difficulties navigating this site? … This alone caught my attention in to the course immediately because I knew at that moment that Dr. Bartfay will be there to assist me if I run into any difficulty and that she will try to help to the best of her abilities, I really liked that.
  • Throughout this course a lot of fantastic work has been made. By using the work we, as a class, have created, my goal in this reflection is to share the content which I have learned in the most unique way as possible.
  • In our textbook, the definition of epidemiology is defined as the study of the distribution and determinants of health-related states or events in human populations and the application of this study to the prevention and control of health problems. What this means is that epidemiology is the study of diseases, why they happen, how they happen and how we can prevent or treat them.
  • What does epidemiology mean to me? Epidemiology is a huge part in the discovery of all knowledge which we know today about different diseases and infections. As mentioned from my very first blog post, I am interested in pursuing the field of Health Informatics; which utilizes and conducts the ideas given to us by Hippocrates. By carefully observing, recording and analysing data, a health informaticist is able to see trends within the samples and as a result can adjust the studies undertaken to focus on particular sections of the original (parent) study.A prime example as to how epidemiology helps the field of health informatics is shown by Parsa Mirhaji, M.D., director at the Center for Biosecurity and Public Health Informatics Research at The University of Texas School of Health Information Sciences created the “Situational Awareness and Preparedness for Public Health Incidences Using Reasoning Engines (SAPPHIRE)”. This system had its first pilot test during the aftermath of Hurricane Katrina back in 2005. The results exceeded expectations, the system worked and monitored and analyzed public health information for the usage of government officials and services, which feared outbreaks of epidemics. The government officials on the rescue teams utilized hand-held computers to gather data from the people being evacuated and transmitted the information directly to the SAPPHIRE database.
  • The role of epidemiology in public health practices is extremely important as it plays a roll in meeting the goals and guidelines for promoting physical, mental and social well-being within the population. The findings from epidemiological case studies contribute to our knowledge of the disease which then in turn aids us in preventing, controlling and treating the disease. Efficacy and Effectiveness help in evaluating the prevention or control program(s). Efficacy refers to the ability of a program to produce a desired effect where as efficiency refers to the ability of the program to work. An example of this is James Lind and his study of Scurvy in 1753. Lind gave each of the six pairs a food to eat as well as their normal rations. The efficacy was to see which of the foods helps to cure Scurvy in the quickest possible way, were the efficiency was shown when multiple foods worked just at different speeds.
  • These three originally gave me some confusion as I was trying to learn them. After some practice however, I finally learned the difference:Epidemic: the occurrence of cases of an illness, specific health-related behaviour, or other health-related events clearly in excess of normal expectancy in the community (an example of this is cholerea)Endemic: the ongoing, usual or constant presence of a disease in a community (an example of this is the HIV/AIDS affecting Africa)Pandemic: is an epidemic affection or attacking the population of an extensive region, country or continent (an example of a this is the Spanish flu)
  • The epidemiological triangle is a model used show the relationships between the host, the environment and the infectious agent over the time axis. This model shows that the all three aspects, so the host, agent and the environment, are all interconnected to how the disease can spread or infect the population. The Agent is the cause of the disease, the host is an organism is usually a human or animal which harbours the disease and the environment includes the surroundings and external conditions which can cause transmission, and last but not least is the variable of time which accounts for incubation periods.
  • There are many ways for a disease to be spread. One of the ways is through a fomite, which is an object such as door handle. Another way is through a vector, such as a mosquito. The third way is through a reservoir, which is a habitat. The fourth way is through a vehicle, which is a nonliving intermediate such as a fomite, water supply or anything that can covey the agent to a host. The last way for a disease to spread is by a carrier, which is an organism which harbours the disease until it spreads (which is usually by airborne follicles).
  • Due to the studies of past epidemiologists, we have been able to create three levels of prevention to protect us from diseases; primary, secondary and tertiary prevention.Primary prevention is preventing a disease or disorder prior to it happening. This can be done through health promotion, health education and health protection within the community. If we can educate the public and explain to them the risks, we can make a healthier population.Secondary prevention is aimed at the health screening and detection activities used to identify disease. Once we identify the disease, we can then act to treat it and further prevent it from occurring again.Tertiary prevention is the limiting of disability by providing rehabilitation where a disease or invention. This level of prevention focuses strictly on treatment of the case
  • As I am sure you can see by this information so far, epidemiology is a crucial aspect in the health of the public. By understanding diseases we can work to understand how they operate, why they occur, how we can prevent them, and how we can treat them.
  • Hippocrates was a physician who later became known as the father of modern day medicine and was the first epidemiologist. Hippocrates was titled the first epidemiologist because he was interested in discovering why people got sick as well as how to cure them. Hippocrates made notes of everything he did and as a result of his efforts, we were able to translate them to create the foundation of epidemiology we have today.
  • James Lind was a Scottish naval surgeon who saw sailors being affected from Scurvy and decided to research it. On his expedition were twelve infected patients, which he divided into groups of two. Lind, on top of their diets, gave each pair an extra food or beverage and recorded the results over time. The six added foods or beverages consisted of a quart of cider, vinegar, sea water, lemons and oranges, elixir, garlic, horseradish and mustard seed. As a result of Lind’s study, the pair who had the extra lemons and oranges recovered the fastest. James Lind, although wanting to help people affected by scurvy and prevent others from developing it, wanted to figure out the background and the nature of scurvy. He wanted to know who it was mainly affecting – the sailors, what is was – a disease which developed as a result of low levels in vitamin c, where it was occurring – sea expeditions, when it was occurring - the months of April, May and June when there was more foggy, cold and rainy weather, why it was occurring – severe lack of vitamin c, and how he could cure it – experimented with six types of different foods/beverages in additions to the sailor’s diets. Lind, whether he knew about it or not, conducted an epidemiological study which, as a result, has given us the knowledge today to be able to cure and fight against scurvy.
  • One of my colleagues, Courtney Shields, did her presentation on John Snow and his study of cholera. She noted that Snow was a British man born in 1813, known for being an astonishing anesthesiologist who determined that the human body responds to anesthetic drugs. Courtney also mentioned that Snow developed many epidemiologic approaches and concepts through his work one the two major cholera outbreaks in London, England. Snow studied cholera and analytically wrote a report which he concluded from his study and learned why cholera came about, how to treat it and how to prevent it.
  • That was just to name a few of the many epidemiologists which have made discoveries which have changed the views of medical science to what we know today. There are so many more which we can look at, however due to the sheer number of them, I have only chose to discuss these three.
  • When an infectious disease is contagious, or capable of being spread, it is classified as a communicable disease. When the disease is not contagious, or not able to be spread, it is classified as a noncommunicable disease. The classification of communicable disease can be broken down further to vertical transmission and horizontal transmission. Vertical transmission is where the disease is past on from parent to offspring through sperm, placenta, milk or vaginal fluids. Horizontal transmission is where infectious agents is what passes the disease onto the host.
  • There are five categories when classifying diseases; Congenital and Hereditary,Allergies and Inflammatory, Degenerative, Metabolic, and Cancer. Congenital and Hereditary diseases are often caused by genetic and familial tendencies. Allergies and Inflammatory diseases are caused by the body reacting to an invasion of or an injury by a foreign object or substance. Degenerative diseases cause a lower level of mental, physical or moral state than is normal. Metabolic diseases cause a dysfunction, poor function or a malfunction of certain organs or physiologic processes of the body. Cancer is a collective name that refers to a group of many diseases with one common characteristic: uncontrolled cell growth or the loss of the cell’s ability to preform apoptosis.
  • Prevention and control of infectious and contagious diseases are the foundation of all public health measures. The three key factors to preventing and controlling diseases are removing, eliminating or containing the source of infection, disrupting and blocking the chain of disease transmission, and protecting the susceptible population against the infection and disease.
  • There are many types of diseases, both known and unknown, as an epidemiologist, it is important to learn as much as possible about these diseases and how they relate to one another so they can be properly categorized and protected against.
  • Descriptive epidemiology involves careful observation, definitions, measurements, interpretations, and dissemination of health-related states by person, place or time. A descriptive study assists us in providing information about the disease or condition, provides us clues in identifying the disease, identifying the extent of the health effect, obtaining a description of the public health problem, identifying the population which is at the greatest risk, and identifies the avenues for further research that can provide insights about an etiologic relationship between an exposure and a health outcome.
  • Nominal data is unordered data categories or classes such as gender, ethnicity etc.Ordinal data is the order among the categories providing addition information such as the stage or grade of cancer.Discrete data are integers that differ by fixed amounts, with no intermediate values possible such as the new cases of lung cancer reported in the US in the last year.Continuous data is measurable quantities not restricted to taking on an integer value such as one’s age.
  • Analytic studies evaluate one or more predetermined hypotheses about associations between exposure and outcome variables. These studies are conducted using a comparison group to establish and discover the Cause-Effect relationship of diseases.
  • There are many different kinds of studies. Once a study has been conducted, a new study may be conducted using the data gathered in another study to view similarities between diseases and how they can relate to one another.
  • Descriptive data on the person level characterizes who is becoming affected by the disease. Most of the focus in epidemiology is on the person aspect of the disease, disability, injury and death.Descriptive data by place addresses where the health related states are occurring.Descriptive data by time have vast ranges from hours to decades and are usually referred to as temporal aspects of time-related elements or issues.
  • Public health surveillance is the ongoing collection, analysis, interpretation, and dissemination of health data. Surveillance data is a means for evaluating changes in health-related states or events which occur regularly and can be predicted or are unusual events which are unexpected.
  • Descriptive epidemiology gives us a means to evaluate and record the gathered data in a manor that can be compared for future studies using keywords and key aspects on the studies.
  • A health indicator is a marker of health status (physical or mental disease, impairments or disability, and social well-being),service provision, or resource availability. It is designed to enable the monitoring of health status, service performance, and/or program goals. Health indicators are a complimentary to a study and in combination reflect the broad scope of health.
  • When looking at the community of a given population, it is important to look at the birth rates and mortality rates to gain a better understanding as to what the population is dealing with without the disease. Then you will have a better piece of mind as to how big of an effect the disease is having. The birth rate in a given area may be influenced by governmental policies, social beliefs, religious beliefs, abortion rates, poverty or economic prosperity, literacy, infant death rates, conflicts (such as war or safety) and urbanization. Birth rate is the ratio of total live births to total population in a given area over a specified time period. The mortality is the epidemiologic and vital statistics term for death. In our society there are three things which can cause death: degeneration of vital organs and related conditions, disease states and society or the environment (homicide, accidents, disasters etc.).
  • Looking at the population (birth rates vs. mortality rates) as well as the health history of the population will be able to inform the epidemiologist of the foundation for their study. From there they will be able to the effect in which the disease or condition has on the public.
  • There are many ways to design an epidemiological study, however there are four main study designs and two sub-categories for each of them. A clinical trial is used to evaluate the efficacy and safety of a new drug or a new medical procedure. A prophylactic trial is used to evaluate preventive measures. Therapeutic trials are used to assess new treatment methods. Community trials is used to test a group intervention designed for the purpose of educational and behavioral changes at the population level. The two sub-categories are between-group design and within-group design. The between group design is where outcomes are compared between two or more groups of people receiving different levels of the intervention. The within group design may also be used where the outcome in a single group is compared before and after the assigned intervention.
  • When the study group is determined, in an ideal situation the participants are then assigned to the intervention and control groups by random assignment. Random assignment makes intervention and control groups look as similar as possible, thereby minimizing the potential influence of confounding factors. With random assignment, chance is the only factor that determines group assignment, thus allowing the application of inferential statistical tests of probability and determination of the levels of significance. Randomized controlled trials are the most common type of clinical trial conducted in clinical settings because it allows for variable results depending on who is chosen at random.
  • Binding is used in experimental studies to minimize any potential bias from the placebo effects. A placebo is a substance containing no medication or treatment given to satisfy a patient’s expectation to get well. The placebo effect is the effect on patient outcomes that a particular intervention will have an effect.
  • There are multiple reasons to not choose a random assignment. Firstly, large research populations are not always available, especially in clinical settings because of how expensive research is. Another restraint is the lack of participants with the disease or condition or a desire to participate. The third reason is that you can’t use randomization is the entire population is to be affected. The fourth reason is randomization is not used in the enforcement of the law. The fifth reason is that a concurrent comparison group can be used when randomization is not feasible.
  • Too add to the sheer number of ways to conduct a study, the way the data can be gathered also varies depending on the type of collection used in the study.
  • Epidemiological studies often utilize sample data from a population of interest. A sample is a subset of items which have been taken from the population. Samples are often studied instead of the population because samples can be studied quicker due to a smaller number, samples are often less expensive because it is a smaller group, the entire population may be impossible, samples can be more reliable forms of data since more time and resources can be spent on them and samples of the population reflect specific characteristics may be appropriate for studying health-related state or events. Statistical inference refers to a conclusion about a population based on sampled data. With sample data we can make probability statements about observations in a study such as that we have a 95% confidence interval.
  • The hypothesis is the statement about health information which is studied and proven to be correct or incorrect. In order to develop the hypothesis is generated through inductive reasoning. Inductive reasoning relies on exact and correct observation, accurate and correct interpretation of the facts in order to understand findings and their relationship to each other and to causality, clear, accurate, and rational explanations of findings, information and facts in reference to causality, and finally, the development based on scientific approaches using facts in the analysis and in a manner that makes sense based on rational scientific knowledge. To test a hypothesis, one would follow the six steps. Step 1 is the formulate the null hypothesis which is the assumed statement. Step 2 is to formulate the alternative statement, which is usually the opposite of the null hypothesis. Step 3 is to select the level of significance for the statistical test, usually 95% confident. Step 4 is to select the appropriate test statistic and identify the degrees of freedom and the critical value(s). Step 5 is to collect the data and estimate the measure of association and the test statistic. Step 6 is to either accept or reject the null hypothesis based of the statistical results and determines the outcome of the study.
  • By utilizing statistics to test our hypotheses, we have the ability to test and compare one or more similar studies and then conclude the confidence interval as well as the overall result of the study.
  • Epidemiologic field investigations usually involve a disease outbreak which is confined to a localized population and have been traced to a common source, outbreaks that have spread from person to person, or a combination of the two. In order to prepare for field work, the research team needs their appropriate scientific knowledge, supplies and equipment; appropriate administrative arrangements are made and consultation roles established. The steps to conducting a field investigation are shown in table 10-1 in our textbook. Step 1 is to prepare for the field work, step 2 is to establish the existence of the outbreak, step 3 is to confirm the diagnosis, step 4 is to establish criteria for case investigation, step 5 is to search for missing cases, step 6 is to count the number of cases, step 7 is to orient the data according to person, place and time, step 8 is the classify the epidemic, step 9 is to determine who is at risk, step 10 is to formulate the hypothesis, step 11 is to test the hypothesis, step 12 is to develop reports to inform people of findings, step 13 is to maintain surveillance to monitor trends and step 14 is to carry out administration and planning activities.
  • Chronic disease epidemiology involves the study of the distribution and determinants of chronic diseases and conditions in human populations and the application of that study to prevent and control these diseases and conditions. In contrast with acute diseases, chronic diseases tend to be less severe but occur over a long duration.
  • Clinical epidemiology focusses on patients and the application of epidemiologic methods to assess the efficacy of screening, diagnosis, and treatment in clinical settings. The primary aim of clinical epidemiology is to identify the health consequences of employing a test or administering a treatment.
  • Medical screening is used to suggest or detect a disease among individuals in a target population without signs or symptoms of the health issue. Medical diagnosis works as a compliment to screening as it is the test to see if the screening was correct or not.
  • Since the screening tests are not perfect, there is margin for error. A True Positive is indicating a person has the disease when, in fact, they do. This can lead to needed treatment and care. True Negative is indicating a person does not have the disease but in reality they do not. This is the preferred situation. False positive is indicating a person has the disease but fact they do not. This can cause unnecessary stress, anxiety and treatment. False Negative indicates a person does not have the disease but in fact they do. This can cause a false sense of security and a lack of needed care and treatment.
  • Even though this course was an introduction to the field of epidemiology, and that we just barely scratched the surface of its vast inner workings, I have learned a lot and will continue to embrace the study of epidemiology throughout my career as a health professional. I want to thank-you for taking the time to view my personal reflection presentation. I do hope that you enjoyed viewing it as much as I enjoyed making it! Thank-you!

Litman emil 100427053_majorindividualassignment Litman emil 100427053_majorindividualassignment Presentation Transcript

  • Outline0 Foundations0 Historic Developments0 Practical Disease Concepts0 Design Strategies and Statistical Methods0 Descriptive Epi0 General Health and Population Indicators0 Experimental Studies0 Causality0 Field Epi0 Chronic Disease Epi0 Clinical Epi
  • Definition of Epidemiology What Epidemiology means to meRole of Epidemiology in Public HealthEpidemics, Endemics and Pandemics Epidemiology Triangle Disease Transmission Levels of Prevention
  • Definition of Epidemiology0 the study of the distribution and determinants of health-related states or events in human populations and the application of this study to the prevention and control of health problems
  • What Epidemiology Means to Me0 Epidemiology and Health Informatics0 SAPPHIRE
  • Role of Epidemiology in Public Health0 Findings contribute to: 0 Preventing disease 0 Controlling disease 0 Treating disease0 Efficacy0 Effectiveness
  • Epidemics, Endemics and Pandemics0 Epidemics0 Endemics0 Pandemics
  • Epidemiology Triangle0 Environment0 Host0 Agent
  • Disease Transmission0 Fomite0 Vector0 Reservoir0 Vehicle0 Carrier
  • Levels of Prevention0 Primary Prevention0 Secondary Prevention0 Tertiary Prevention
  • HippocratesJames Lind and ScurvyJohn Snow and Cholera
  • Hippocrates0 Who was he?0 Why is he important?
  • James Lind0 Who was he?0 What did he do?
  • John Snow0 Who was he?0 Why was he important?
  • Diseases and Conditions Classifying DiseasesDisease Prevention and Control
  • Diseases and Conditions0 Communicable VS Noncommunicable0 Vertical VS Horizontal Transmission
  • Classifying Diseases0 Congenital and Hereditary0 Allergies and Inflammatory0 Degenerative0 Metabolic0 Cancer
  • Disease Prevention and Control0 Remove, eliminate or contain the source of infection0 Disrupt and block the chain of disease transmission0 Protect the susceptible population against the infection and disease
  • Descriptive Study Designs Types of Data Analytic Study Designs
  • Descriptive Study Designs0 Providing information0 Clues to identify disease0 Extent of public health issue0 Description of public health issue0 Identifying risk0 Identifying avenues for further research
  • Types of Data0 Nominal0 Ordinal0 Discrete0 Continuous
  • Analytic Study Designs0 Similar to Descriptive Studies0 Use Comparison Groups
  • Person, Place and TimePublic Health Surveillance
  • Person, Place and Time0 Person0 Place0 Time
  • Public Health Surveillance0 What is it?
  • Health IndicatorBirth and Mortality
  • Health Indicator0 What is it?0 What is it for?
  • Birth and Mortality0 Why is this important?0 Birth Rate0 Mortality Rate
  • Designs Randomization BindingNonrandomization
  • Designs0 Clinical Trial0 Prophylactic Trial0 Therapeutic Trial0 Community Trial0 Between-Group Design0 Within-Group Design
  • Randomization0 What is randomization?0 Why is it beneficial?
  • Binding0 What is a binding?0 Placebo0 Placebo effect
  • Nonrandomization0 Why use nonrandomization and not randomization?
  • Statistical InferenceHypothesis Development and Testing
  • Statistical Inference0 What is statistical inference?0 Why use samples instead of the entire population?
  • Hypothesis Development and Testing0 Start of all epidemiological studies0 Inductive reasoning0 6 steps of testing
  • Conducting a Field Investigation
  • Conducting a Field Investigation0 When are field investigations conducted0 Preparing for field word0 Steps to conduct (14)
  • Chronic Disease Epidemiology
  • Chronic Disease Epidemiology0 What is it?
  • Clinical Epidemiology Screening and DiagnosisEvaluating the Screening Test
  • Clinical Epidemiology0 What is it?0 What is its focus?
  • Screening and Diagnosis0 What are these tools used for?
  • Evaluating the Screening Test0 True Positive0 True Negative0 False Positive0 False Negative
  • Bibliography0 Cahill, R., & Advancement, I. (n.d.). Distinctions - Biosecurity System Improves Public Health Surveillance, Decision Making. The University of Texas Health Science Center at Houston (UTHealth) - Home. Retrieved January 14, 2013, from 7/may/archive.htm?id=792574.0 Merrill, R.M. (2013). Introduction to Epidemiology (6th ed., pp. 2-4). Toronto, Canada.: Jones and Bartlett Publishers.