An outbreak of endophthalmitis has occurred in patients who underwent surgery at a district hospital. The document discusses how to investigate this outbreak using different study designs. It recommends using a case-control study design to evaluate the association between surgery at the hospital and developing endophthalmitis. It provides details on how to conduct a case-control study, including selecting cases and controls, collecting exposure data, and calculating odds ratios to assess strength of association.
This document outlines different types of epidemiological study designs including observational studies like descriptive studies, analytical studies, ecological studies, cross-sectional studies and case-control studies. It also discusses experimental study designs like randomized controlled trials, field trials and community trials. Key features and steps are provided for case-control studies and cohort studies. Sources of bias and errors in epidemiological studies are also summarized.
A cohort study follows groups of individuals (the cohorts) over time to examine how exposures affect outcomes. Key features include:
1. Cohorts are identified prior to the outcome and followed prospectively to determine disease frequency.
2. Cohort studies directly estimate relative risks by comparing disease incidence between exposed and unexposed groups.
3. They provide data on disease progression, risk factors, and natural history that can inform prevention strategies by identifying modifiable risk exposures.
This document discusses different study designs used in biomedical research. It begins by describing descriptive study designs including case reports, case series, cross-sectional studies, and ecological studies. It then covers analytical study designs like cohort and case-control studies. Finally, it discusses experimental study designs, focusing on randomized controlled trials. Key points include how these different designs compare in terms of strengths and limitations, and which designs provide the strongest evidence to answer particular research questions.
2010-Epidemiology (Dr. Sameem) basics and priciples.pptAmirRaziq1
Epidemiology is the study of the distribution and determinants of health-related states in populations. There are three main types of epidemiological studies: observational studies which examine risk factors without interfering; experimental (interventional) studies which manipulate factors; and descriptive studies which show disease patterns and frequencies. Case-control studies are retrospective and compare exposures in cases (diseased) and controls (non-diseased) to identify risk factors. Cohort studies are prospective and follow exposure groups over time to calculate disease incidence and identify risk factors. Cross-sectional studies provide a snapshot of disease prevalence and help generate hypotheses for further research.
A cohort study involves following groups of individuals over time to examine exposure and disease status. Cohort studies compare disease incidence between exposed and unexposed groups. Key aspects include selecting cohorts based on exposure status, obtaining exposure data, following cohorts over time to measure disease outcomes, and analyzing results by calculating incidence rates and relative risks. Advantages are the ability to establish temporal relationships and measure multiple outcomes, while disadvantages include time and cost requirements and potential for loss to follow-up.
This document discusses different study designs used in medical research, including observational studies and randomized controlled trials. Observational studies include cohort studies, case-control studies, and cross-sectional studies. Cohort studies follow groups over time to assess outcomes. Case-control studies compare groups with/without an outcome. Cross-sectional studies measure outcomes at one time point. Randomized controlled trials randomly assign participants to intervention/control groups to minimize bias when assessing cause-and-effect relationships. Key aspects of randomized trials discussed include equipoise, randomization, blinding, intention-to-treat analysis, and different trial designs.
Etiologic research aims to establish causal relationships between determinants and disease outcomes. There are two main observational study designs for etiologic research: cohort studies and case-control studies. Cohort studies follow groups of individuals over time based on exposure to a determinant and compare disease outcome rates. Case-control studies identify cases of a disease and controls without the disease and compare past exposure to determinants. Both study designs are prone to biases like selection bias, information bias, and confounding, which can distort the true determinant-outcome relationship if not adequately addressed.
This document outlines different types of epidemiological study designs including observational studies like descriptive studies, analytical studies, ecological studies, cross-sectional studies and case-control studies. It also discusses experimental study designs like randomized controlled trials, field trials and community trials. Key features and steps are provided for case-control studies and cohort studies. Sources of bias and errors in epidemiological studies are also summarized.
A cohort study follows groups of individuals (the cohorts) over time to examine how exposures affect outcomes. Key features include:
1. Cohorts are identified prior to the outcome and followed prospectively to determine disease frequency.
2. Cohort studies directly estimate relative risks by comparing disease incidence between exposed and unexposed groups.
3. They provide data on disease progression, risk factors, and natural history that can inform prevention strategies by identifying modifiable risk exposures.
This document discusses different study designs used in biomedical research. It begins by describing descriptive study designs including case reports, case series, cross-sectional studies, and ecological studies. It then covers analytical study designs like cohort and case-control studies. Finally, it discusses experimental study designs, focusing on randomized controlled trials. Key points include how these different designs compare in terms of strengths and limitations, and which designs provide the strongest evidence to answer particular research questions.
2010-Epidemiology (Dr. Sameem) basics and priciples.pptAmirRaziq1
Epidemiology is the study of the distribution and determinants of health-related states in populations. There are three main types of epidemiological studies: observational studies which examine risk factors without interfering; experimental (interventional) studies which manipulate factors; and descriptive studies which show disease patterns and frequencies. Case-control studies are retrospective and compare exposures in cases (diseased) and controls (non-diseased) to identify risk factors. Cohort studies are prospective and follow exposure groups over time to calculate disease incidence and identify risk factors. Cross-sectional studies provide a snapshot of disease prevalence and help generate hypotheses for further research.
A cohort study involves following groups of individuals over time to examine exposure and disease status. Cohort studies compare disease incidence between exposed and unexposed groups. Key aspects include selecting cohorts based on exposure status, obtaining exposure data, following cohorts over time to measure disease outcomes, and analyzing results by calculating incidence rates and relative risks. Advantages are the ability to establish temporal relationships and measure multiple outcomes, while disadvantages include time and cost requirements and potential for loss to follow-up.
This document discusses different study designs used in medical research, including observational studies and randomized controlled trials. Observational studies include cohort studies, case-control studies, and cross-sectional studies. Cohort studies follow groups over time to assess outcomes. Case-control studies compare groups with/without an outcome. Cross-sectional studies measure outcomes at one time point. Randomized controlled trials randomly assign participants to intervention/control groups to minimize bias when assessing cause-and-effect relationships. Key aspects of randomized trials discussed include equipoise, randomization, blinding, intention-to-treat analysis, and different trial designs.
Etiologic research aims to establish causal relationships between determinants and disease outcomes. There are two main observational study designs for etiologic research: cohort studies and case-control studies. Cohort studies follow groups of individuals over time based on exposure to a determinant and compare disease outcome rates. Case-control studies identify cases of a disease and controls without the disease and compare past exposure to determinants. Both study designs are prone to biases like selection bias, information bias, and confounding, which can distort the true determinant-outcome relationship if not adequately addressed.
This document discusses the design and methodology of case-control studies. It defines a case-control study as one where subjects are selected based on whether they have or do not have a disease. The document outlines the specific objectives, basic design, and steps in conducting a case-control study including selection of cases and controls, matching, measuring exposure, and analyzing the data through calculating odds ratios. It also discusses sources of bias and the advantages and disadvantages of this study design.
This document discusses various types of epidemiological study designs. It describes observational studies like case studies, case series, cross-sectional studies and ecological studies which are descriptive in nature. Analytical observational studies include case-control and cohort studies. Experimental studies involve intervention and comparison groups like randomized controlled trials. The stages of epidemiological investigations are also outlined, from the diagnostic and descriptive phases to the analytical, intervention, decision-making and monitoring phases. Common epidemiological terms like relative risk, odds ratio and attributable risk are defined.
This document discusses experimental studies and randomized clinical trials. It defines clinical trials as medical research studies conducted with human subjects to evaluate new interventions. Randomized clinical trials are described as the gold standard for comparing an intervention to a placebo or control group by randomly assigning subjects to each. The basic steps of a randomized clinical trial are outlined as drawing up a protocol, selecting study populations, randomizing subjects, administering the intervention, follow up, and assessment of outcomes. Advantages include providing evidence of causality, while disadvantages include cost and sample size requirements. Methods to reduce bias like randomization and blinding are also described.
This document provides an overview of case-control studies in epidemiology. It discusses the key steps in conducting a case-control study, including selecting cases and controls, measuring exposure, and analyzing the data. Some advantages are that case-control studies are relatively inexpensive and allow investigation of rare diseases. However, they are subject to biases related to recall and selection of appropriate controls. In conclusion, the case-control design is a useful method for investigating hypotheses about disease causation in epidemiology.
This document discusses various epidemiological study designs. It begins by defining descriptive studies, which involve systematically collecting and presenting data to describe a situation, and analytical studies, which attempt to establish causes or risk factors by comparing exposed and unexposed groups. The main types of descriptive studies covered are cross-sectional (examining a population at a single point in time), longitudinal (following a population over time), and ecological (examining population-level associations between exposures and outcomes). Advantages and disadvantages of each design are provided.
This document provides an overview of cohort studies. It defines a cohort study as observing a group of people who share a common characteristic or experience over time to study the frequency of disease. The key features discussed include: identifying cohorts prior to disease, observing cohorts prospectively to study cause-effect relationships, minimizing attrition, and comparing exposed and non-exposed groups. The document also covers types of cohort studies, elements of cohort studies like follow-up, and strengths such as establishing causation but also weaknesses like loss to follow-up.
This document discusses various study designs used in epidemiology, including measures of disease occurrence such as prevalence and incidence. It defines prevalence as the total number of cases of a disease at a specified time, while incidence refers to the number of new cases that occur over a period of time. Cohort studies are described as following groups over time to compare rates of an outcome between those exposed and unexposed to a factor. Case-control studies select groups based on having or not having an outcome and look back to compare exposures. Biases such as selection, information and confounding are also outlined.
This document outlines different types of epidemiologic study designs, including descriptive studies like case reports, case series, and cross-sectional studies which collect data to describe disease occurrence but cannot determine causality. Analytical studies like case-control and cohort studies seek to identify associations between exposures and outcomes. Experimental studies use deliberate interventions to establish causality. Each design has strengths and limitations related to bias, ability to determine causality, required resources, and generalizability.
This document discusses different epidemiological study designs used to study the distribution and determinants of health-related events in populations. It describes descriptive epidemiology which observes disease distribution and identifies associated characteristics. Descriptive studies define the population, disease, measure disease occurrence and describe patterns. Analytical epidemiology comprises observational case-control and cohort studies, which can determine associations between disease and suspected factors. Case-control studies compare exposure in cases vs controls, while cohort studies follow groups over time from exposure to disease. Their strengths and limitations are provided.
This document discusses case control and cohort studies. A case control study is a retrospective observational study that compares exposures in cases (people with a disease) to controls (people without the disease). Key steps include selecting cases and controls, measuring exposure, and calculating odds ratios to estimate disease risk. A cohort study is a prospective observational study that follows groups over time to determine disease frequencies. Cohorts are identified and data on exposure is collected before outcomes occur. Incidence rates and relative risks are calculated by comparing disease occurrence between exposed and unexposed groups. Both study designs have advantages and disadvantages for estimating disease risk factors.
This document provides an overview of different types of clinical study designs, including observational studies and experimental studies. It discusses the key aspects and objectives of different phases of clinical trials, including:
1. Phase I trials which aim to determine safety and maximum tolerated dose of new therapies.
2. Phase II trials which provide preliminary evidence of efficacy through surrogate endpoints and further evaluate safety.
3. Phase III trials which are comparative effectiveness trials that use clinical outcomes like survival to compare new treatments to standard of care through randomized controlled designs.
This document provides an overview of different study designs including observational and experimental designs. It defines key observational designs like case reports, case series, ecological studies, cross-sectional studies, case-control studies and cohort studies. It notes their strengths and weaknesses. Experimental designs discussed include randomized controlled trials and their key elements like selection of subjects, allocation of exposure, blinding and analysis. Clinical trial phases and ethical principles in trials are also summarized.
Case control studies allow researchers to study exposures associated with particular outcomes by comparing exposures in individuals who have the outcome (cases) to those who do not (controls). They are best suited for rare outcomes or when exposure data is difficult to obtain. Cases and controls are selected and their past exposures are compared to identify associations. Controls should represent the same base population as cases. Case control studies can efficiently study rare diseases and diseases with long induction periods, and evaluate multiple exposures, but are limited by potential recall bias due to their retrospective nature.
The document discusses different types of epidemiological studies, including descriptive studies like case reports and case series that focus on person, place and time to create hypotheses. Analytical studies like case-control and cohort studies are used to test hypotheses by being either observational or interventional. Randomized controlled trials are the gold standard for comparing new interventions. Observational analytical studies include cross-sectional, cohort and case-control designs, while interventional analytical studies are clinical trials. The appropriate study design depends on the research goals and objectives.
Screening involves testing apparently healthy individuals to detect unrecognized disease. It aims to identify disease at earlier, more treatable stages through simple, rapid and low-cost tests. An ideal screening test should accurately detect the target condition, have a high yield of positive results, and be acceptable to the population. Screening criteria include addressing an important health problem, having a recognizable pre-symptomatic stage, and providing early treatment that reduces disease burden. Evaluation of screening tests considers their sensitivity, specificity, and predictive values to determine how well results identify individuals with and without the disease. The cut-off point for positive results impacts the balance between false positives and negatives.
This document discusses different types of study designs used in medical research, including qualitative and quantitative methods. It covers observational studies like cohort and case-control studies, as well as experimental designs like randomized controlled trials. For each study type, it outlines their purpose, strengths, weaknesses and the types of research questions they can help answer. The goal is to help researchers choose the most appropriate design based on their specific research question and aims.
This document discusses different types of epidemiological study designs including analytic, observational, and interventional studies. It provides details on cohort and case-control study designs, including how to select cases and controls, measure exposures and outcomes, analyze results, and consider advantages and limitations. It also defines various measures of mortality such as crude death rate, age-specific mortality rate, and case fatality rate.
Research Methods 2 for Midwifery students .pptxEndex Tam
The document discusses measures of association in case-control studies and cohort studies. It defines odds ratio as the measure of association in case-control studies, which compares the odds of disease in the exposed group to the odds of disease in the unexposed group. Cohort studies follow disease-free groups over time to compare incidence of disease between exposed and unexposed cohorts. The relative risk is used to measure association in cohort studies by comparing incidence rates of disease between exposed and unexposed groups. The document also discusses experimental study designs, sampling methods, and how to determine sample size.
This document discusses various epidemiologic study designs used to identify and investigate risk factors for disease. Descriptive designs like case reports, case series, and cross-sectional studies measure disease frequency and exposure levels. Analytic designs like case-control and cohort studies attempt to specify disease causes. Case-control studies identify existing diseases and look back at previous exposures, while cohort studies follow subjects over time to compare disease incidence between exposed and unexposed groups. Experimental studies randomly allocate subjects to exposure groups to establish causality but have ethical and cost disadvantages compared to observational designs. The appropriate study design depends on factors like the question, resources, disease frequency, and data quality.
This document provides an overview of the history and evolution of medicine. It describes how medicine originated from primitive practices involving supernatural beliefs. It then discusses the development of early systems of medicine in places like India, China, Egypt, and Mesopotamia. Key figures that advanced medical knowledge are highlighted from each era, such as Susruta, Hippocrates, Galen, Ibn Sina, and Pasteur. Major milestones like the germ theory of disease and advances in preventive medicine through vaccination are also summarized. The document concludes by describing the modern fields of curative, preventive, and social medicine.
This document discusses various types of communication including one-way communication, two-way communication, verbal communication, non-verbal communication, formal and informal communication, and visual communication. It also addresses telecommunication, barriers to communication, functions of health communication, approaches to health education, principles of health education, and methods used in health communication including individual, group, and mass approaches.
This document discusses the design and methodology of case-control studies. It defines a case-control study as one where subjects are selected based on whether they have or do not have a disease. The document outlines the specific objectives, basic design, and steps in conducting a case-control study including selection of cases and controls, matching, measuring exposure, and analyzing the data through calculating odds ratios. It also discusses sources of bias and the advantages and disadvantages of this study design.
This document discusses various types of epidemiological study designs. It describes observational studies like case studies, case series, cross-sectional studies and ecological studies which are descriptive in nature. Analytical observational studies include case-control and cohort studies. Experimental studies involve intervention and comparison groups like randomized controlled trials. The stages of epidemiological investigations are also outlined, from the diagnostic and descriptive phases to the analytical, intervention, decision-making and monitoring phases. Common epidemiological terms like relative risk, odds ratio and attributable risk are defined.
This document discusses experimental studies and randomized clinical trials. It defines clinical trials as medical research studies conducted with human subjects to evaluate new interventions. Randomized clinical trials are described as the gold standard for comparing an intervention to a placebo or control group by randomly assigning subjects to each. The basic steps of a randomized clinical trial are outlined as drawing up a protocol, selecting study populations, randomizing subjects, administering the intervention, follow up, and assessment of outcomes. Advantages include providing evidence of causality, while disadvantages include cost and sample size requirements. Methods to reduce bias like randomization and blinding are also described.
This document provides an overview of case-control studies in epidemiology. It discusses the key steps in conducting a case-control study, including selecting cases and controls, measuring exposure, and analyzing the data. Some advantages are that case-control studies are relatively inexpensive and allow investigation of rare diseases. However, they are subject to biases related to recall and selection of appropriate controls. In conclusion, the case-control design is a useful method for investigating hypotheses about disease causation in epidemiology.
This document discusses various epidemiological study designs. It begins by defining descriptive studies, which involve systematically collecting and presenting data to describe a situation, and analytical studies, which attempt to establish causes or risk factors by comparing exposed and unexposed groups. The main types of descriptive studies covered are cross-sectional (examining a population at a single point in time), longitudinal (following a population over time), and ecological (examining population-level associations between exposures and outcomes). Advantages and disadvantages of each design are provided.
This document provides an overview of cohort studies. It defines a cohort study as observing a group of people who share a common characteristic or experience over time to study the frequency of disease. The key features discussed include: identifying cohorts prior to disease, observing cohorts prospectively to study cause-effect relationships, minimizing attrition, and comparing exposed and non-exposed groups. The document also covers types of cohort studies, elements of cohort studies like follow-up, and strengths such as establishing causation but also weaknesses like loss to follow-up.
This document discusses various study designs used in epidemiology, including measures of disease occurrence such as prevalence and incidence. It defines prevalence as the total number of cases of a disease at a specified time, while incidence refers to the number of new cases that occur over a period of time. Cohort studies are described as following groups over time to compare rates of an outcome between those exposed and unexposed to a factor. Case-control studies select groups based on having or not having an outcome and look back to compare exposures. Biases such as selection, information and confounding are also outlined.
This document outlines different types of epidemiologic study designs, including descriptive studies like case reports, case series, and cross-sectional studies which collect data to describe disease occurrence but cannot determine causality. Analytical studies like case-control and cohort studies seek to identify associations between exposures and outcomes. Experimental studies use deliberate interventions to establish causality. Each design has strengths and limitations related to bias, ability to determine causality, required resources, and generalizability.
This document discusses different epidemiological study designs used to study the distribution and determinants of health-related events in populations. It describes descriptive epidemiology which observes disease distribution and identifies associated characteristics. Descriptive studies define the population, disease, measure disease occurrence and describe patterns. Analytical epidemiology comprises observational case-control and cohort studies, which can determine associations between disease and suspected factors. Case-control studies compare exposure in cases vs controls, while cohort studies follow groups over time from exposure to disease. Their strengths and limitations are provided.
This document discusses case control and cohort studies. A case control study is a retrospective observational study that compares exposures in cases (people with a disease) to controls (people without the disease). Key steps include selecting cases and controls, measuring exposure, and calculating odds ratios to estimate disease risk. A cohort study is a prospective observational study that follows groups over time to determine disease frequencies. Cohorts are identified and data on exposure is collected before outcomes occur. Incidence rates and relative risks are calculated by comparing disease occurrence between exposed and unexposed groups. Both study designs have advantages and disadvantages for estimating disease risk factors.
This document provides an overview of different types of clinical study designs, including observational studies and experimental studies. It discusses the key aspects and objectives of different phases of clinical trials, including:
1. Phase I trials which aim to determine safety and maximum tolerated dose of new therapies.
2. Phase II trials which provide preliminary evidence of efficacy through surrogate endpoints and further evaluate safety.
3. Phase III trials which are comparative effectiveness trials that use clinical outcomes like survival to compare new treatments to standard of care through randomized controlled designs.
This document provides an overview of different study designs including observational and experimental designs. It defines key observational designs like case reports, case series, ecological studies, cross-sectional studies, case-control studies and cohort studies. It notes their strengths and weaknesses. Experimental designs discussed include randomized controlled trials and their key elements like selection of subjects, allocation of exposure, blinding and analysis. Clinical trial phases and ethical principles in trials are also summarized.
Case control studies allow researchers to study exposures associated with particular outcomes by comparing exposures in individuals who have the outcome (cases) to those who do not (controls). They are best suited for rare outcomes or when exposure data is difficult to obtain. Cases and controls are selected and their past exposures are compared to identify associations. Controls should represent the same base population as cases. Case control studies can efficiently study rare diseases and diseases with long induction periods, and evaluate multiple exposures, but are limited by potential recall bias due to their retrospective nature.
The document discusses different types of epidemiological studies, including descriptive studies like case reports and case series that focus on person, place and time to create hypotheses. Analytical studies like case-control and cohort studies are used to test hypotheses by being either observational or interventional. Randomized controlled trials are the gold standard for comparing new interventions. Observational analytical studies include cross-sectional, cohort and case-control designs, while interventional analytical studies are clinical trials. The appropriate study design depends on the research goals and objectives.
Screening involves testing apparently healthy individuals to detect unrecognized disease. It aims to identify disease at earlier, more treatable stages through simple, rapid and low-cost tests. An ideal screening test should accurately detect the target condition, have a high yield of positive results, and be acceptable to the population. Screening criteria include addressing an important health problem, having a recognizable pre-symptomatic stage, and providing early treatment that reduces disease burden. Evaluation of screening tests considers their sensitivity, specificity, and predictive values to determine how well results identify individuals with and without the disease. The cut-off point for positive results impacts the balance between false positives and negatives.
This document discusses different types of study designs used in medical research, including qualitative and quantitative methods. It covers observational studies like cohort and case-control studies, as well as experimental designs like randomized controlled trials. For each study type, it outlines their purpose, strengths, weaknesses and the types of research questions they can help answer. The goal is to help researchers choose the most appropriate design based on their specific research question and aims.
This document discusses different types of epidemiological study designs including analytic, observational, and interventional studies. It provides details on cohort and case-control study designs, including how to select cases and controls, measure exposures and outcomes, analyze results, and consider advantages and limitations. It also defines various measures of mortality such as crude death rate, age-specific mortality rate, and case fatality rate.
Research Methods 2 for Midwifery students .pptxEndex Tam
The document discusses measures of association in case-control studies and cohort studies. It defines odds ratio as the measure of association in case-control studies, which compares the odds of disease in the exposed group to the odds of disease in the unexposed group. Cohort studies follow disease-free groups over time to compare incidence of disease between exposed and unexposed cohorts. The relative risk is used to measure association in cohort studies by comparing incidence rates of disease between exposed and unexposed groups. The document also discusses experimental study designs, sampling methods, and how to determine sample size.
This document discusses various epidemiologic study designs used to identify and investigate risk factors for disease. Descriptive designs like case reports, case series, and cross-sectional studies measure disease frequency and exposure levels. Analytic designs like case-control and cohort studies attempt to specify disease causes. Case-control studies identify existing diseases and look back at previous exposures, while cohort studies follow subjects over time to compare disease incidence between exposed and unexposed groups. Experimental studies randomly allocate subjects to exposure groups to establish causality but have ethical and cost disadvantages compared to observational designs. The appropriate study design depends on factors like the question, resources, disease frequency, and data quality.
This document provides an overview of the history and evolution of medicine. It describes how medicine originated from primitive practices involving supernatural beliefs. It then discusses the development of early systems of medicine in places like India, China, Egypt, and Mesopotamia. Key figures that advanced medical knowledge are highlighted from each era, such as Susruta, Hippocrates, Galen, Ibn Sina, and Pasteur. Major milestones like the germ theory of disease and advances in preventive medicine through vaccination are also summarized. The document concludes by describing the modern fields of curative, preventive, and social medicine.
This document discusses various types of communication including one-way communication, two-way communication, verbal communication, non-verbal communication, formal and informal communication, and visual communication. It also addresses telecommunication, barriers to communication, functions of health communication, approaches to health education, principles of health education, and methods used in health communication including individual, group, and mass approaches.
This document summarizes key epidemiological factors related to smallpox, chickenpox, and measles. For smallpox, it notes factors that enabled its eradication like lack of animal reservoirs, effective vaccination, and distinctive rash allowing easy detection. For chickenpox, it outlines agent, host, environmental transmission factors and clinical features. For measles, it provides global burden, India statistics, epidemiological determinants like transmission via droplets, and prevention through vaccination or immunoglobulin administration.
This document discusses the importance of communication skills in medical practice. It outlines seven competencies for effective doctor-patient communication: building a relationship, opening the discussion, gathering information, understanding the patient's perspective, sharing information, reaching agreement, and providing closure. For each competency, it provides tips and guidelines on how to demonstrate care, show respect, ask open-ended questions, actively listen, explain diagnoses and plans, and ensure mutual understanding. The overall message is that strong interpersonal communication is integral to quality patient care.
- Influenza is caused by influenza viruses types A, B, and C. Type A causes pandemics every 10-15 years due to antigenic variation. The most recent pandemics were the Spanish Flu in 1918, Asian Flu in 1957, and Hong Kong Flu in 1968.
- Bird flu is caused by the H5N1 virus and can infect humans. It is usually fatal in birds and sometimes infects humans through contact with infected birds. Human to human transmission is rare but possible if the virus mutates.
- SARS is a viral respiratory disease caused by a coronavirus. It emerged in 2002-2003 with symptoms including fever, cough, and difficulty breathing which can progress to pneumonia. It was
Cholera is an acute diarrheal illness caused by the bacteria Vibrio cholerae. It is transmitted through contaminated food or water and causes a rapid loss of fluids and electrolytes through profuse diarrhea. Treatment involves oral or intravenous rehydration to replace lost fluids, along with antibiotics to shorten the duration of illness. Prevention relies on access to clean water, proper sanitation, and hygiene education to reduce transmission.
Cholera is an acute diarrheal disease caused by the bacterium Vibrio cholerae. It remains a global threat, with an estimated 2.9 million cases and 95,000 deaths worldwide annually. The disease spreads through contaminated food and water and can kill within hours if left untreated. Cholera outbreaks typically occur in areas with poor sanitation and lack of clean drinking water. Prevention relies on vaccination, water treatment, hygiene and proper sanitation.
Through lifestyle modifications like diet, exercise, yoga, meditation and stress management, the risk of developing diabetes can be reduced. A healthy diet low in refined carbs and sugar but high in fiber is recommended. Regular exercise of at least 40 minutes per day helps control blood sugar levels. Yoga and meditation lower stress levels and insulin resistance. Proper sleep, social support and avoiding pollution further help in diabetes prevention. Timely screening and lifestyle changes can prevent or delay the onset of diabetes and its complications.
This document provides an overview of descriptive epidemiology. It defines descriptive studies as those that describe the frequency and distribution of an outcome without a comparison group. The main objectives are to describe disease incidence/prevalence, natural history, and distribution according to person, place and time variables. Descriptive studies make hypotheses about causes but do not confirm them. Key aspects include describing disease occurrence by time, place and person; measuring disease burden; and formulating etiological hypotheses.
Cholera is an acute diarrheal illness caused by the bacteria Vibrio cholerae. It causes a rapid loss of fluids and electrolytes from the intestines that can lead to dehydration, shock, and even death if untreated. The classic symptoms include painless watery diarrhea and vomiting. Treatment involves oral or intravenous rehydration to replace lost fluids, along with antibiotics to kill the bacteria. Patients are discharged once they can tolerate oral intake and their diarrhea and urinary output returns to normal levels. Cholera remains a global threat, especially in areas with poor sanitation and lack of clean water.
This document discusses the Dengue Syndrome and summarizes key information about Dengue Fever and Dengue Hemorrhagic Fever. It notes that over 2.5 billion people worldwide live in areas where dengue viruses can be transmitted. The document describes the symptoms, diagnosis, and grading of severity for Dengue Fever and Dengue Hemorrhagic Fever. It also provides information on treatment, control measures, and discusses another similar disease, Chikungunya Fever.
Cholera is caused by the bacteria Vibrio cholerae and is transmitted through contaminated food or water. It causes severe diarrhea and dehydration that can be fatal if untreated. The primary treatment is oral rehydration therapy. Prevention focuses on access to clean water, sanitation, vaccination in high risk areas, and public health education on hygiene practices.
Influenza is an acute respiratory infection caused by influenza viruses types A, B, and C. Type A strains have caused all known pandemics. The virus is highly contagious and spreads rapidly through droplets. It commonly causes epidemics every 2-3 years for influenza A and 4-7 years for influenza B. While most cases are mild, influenza can lead to complications like pneumonia. Vaccination and antiviral drugs can help prevent and treat the disease. Good hygiene and avoiding crowded areas during outbreaks are also recommended.
Cancer is characterized by abnormal cell growth that can invade tissues and spread to distant organs, potentially causing death. The three main types are carcinoma, sarcoma, and leukemia/lymphoma. Worldwide, cancer causes over 6 million deaths annually. In India, the most common cancers are oral, esophageal, stomach and lung cancers in men, and breast, cervical, oral and esophageal cancers in women. Environmental factors like tobacco, alcohol, diet, occupation and infection can increase cancer risk, as can genetic factors. Prevention focuses on reducing risk factors, screening and early detection, and treatment. Breast cancer is the most common cancer in women worldwide. Cervical cancer is also very common in India, where screening programs
Bird flu, or avian influenza, is a viral infection that commonly infects birds like chickens, ducks, and turkeys. The H5N1 strain is particularly deadly and can be transmitted from birds to humans. Symptoms in humans include fever, cough, and possible complications like hypoxemia and organ dysfunction. While human-to-human transmission is rare, there is a risk of mutation allowing easier spread between humans. Treatment involves antiviral drugs, isolation, and supportive care. Prevention focuses on proper handling of infected birds and their products as well as hygiene practices.
This document discusses cancer in general and provides details on certain types of cancers. It covers the characteristics, causes, risk factors, patterns, and control of cancer. Specific cancers discussed in more detail include oral cancer, breast cancer, and cancer of the cervix. Prevention strategies like screening, lifestyle changes, and treatment options are also summarized.
This document summarizes information about Mumps and Rubella.
Mumps is caused by the mumps virus, an RNA paramyxovirus. It causes swelling of the parotid glands. The virus is transmitted through respiratory droplets. Complications can include orchitis. Vaccination with the MMR vaccine provides protection.
Rubella, also known as German measles, is caused by the rubella virus, an RNA togavirus. It causes a rash and lymphadenopathy. Congenital rubella syndrome can occur if a pregnant woman is infected, causing birth defects. The rubella vaccine is a live attenuated vaccine that provides lifelong immunity in 95% of cases.
Global vaccination strategies
This document provides an overview of cancer biology. It discusses how cancer is caused by the accumulation of genetic mutations over time that disrupt normal cell growth regulation. Key points covered include: the genetic and molecular basis of cancer; common properties of cancer cells like uncontrolled growth; the role of oncogenes and tumor suppressor genes; how mutations in growth factors, receptors, and cell cycle regulators can cause cancer; and the multi-hit model of carcinogenesis. The document also examines specific cancer-causing mutations and molecular mechanisms.
This document discusses respiratory infections like smallpox and chickenpox. Smallpox was eradicated in the 20th century through international cooperation and vaccination efforts. Chickenpox is caused by the varicella zoster virus and presents as a rash that spreads from the trunk to the extremities. It most commonly affects children under 10 years old. Complications can occur in immunocompromised individuals. Diagnosis is usually clinical and treatment is supportive.
The document discusses key concepts in epidemiology including descriptive studies, analytical studies, and interventional studies. Descriptive studies involve systematically collecting and presenting data to describe a health situation, such as the occurrence of a disease over time, place, and person. Analytical studies attempt to establish causes or risk factors by comparing groups with and without a problem. Common analytical study designs include case-control and cohort studies. Interventional studies involve manipulating a situation and measuring the effects, with experimental studies using randomization and control groups.
The biomechanics of running involves the study of the mechanical principles underlying running movements. It includes the analysis of the running gait cycle, which consists of the stance phase (foot contact to push-off) and the swing phase (foot lift-off to next contact). Key aspects include kinematics (joint angles and movements, stride length and frequency) and kinetics (forces involved in running, including ground reaction and muscle forces). Understanding these factors helps in improving running performance, optimizing technique, and preventing injuries.
5-hydroxytryptamine or 5-HT or Serotonin is a neurotransmitter that serves a range of roles in the human body. It is sometimes referred to as the happy chemical since it promotes overall well-being and happiness.
It is mostly found in the brain, intestines, and blood platelets.
5-HT is utilised to transport messages between nerve cells, is known to be involved in smooth muscle contraction, and adds to overall well-being and pleasure, among other benefits. 5-HT regulates the body's sleep-wake cycles and internal clock by acting as a precursor to melatonin.
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Since our release of the PGx capabilities in VarSeq, we’ve had a few months to gather some insights from various use cases. Some users approach PGx workflows by means of array genotyping or what seems to be a growing trend of adding the star allele calling to the existing NGS pipeline for whole genome data. Luckily, both approaches are supported with the VarSeq software platform. The genotyping method being used will also dictate what the scope of the tertiary analysis will be. For example, are your PGx reports a standalone pipeline or would your lab’s goal be to handle a dual-purpose workflow and report on PGx + Diagnostic findings.
The purpose of this webcast is to:
Discuss and demonstrate the approaches with array and NGS genotyping methods for star allele calling to prep for downstream analysis.
Following genotyping, explore alternative tertiary workflow concepts in VarSeq to handle PGx reporting.
Moreover, we will include insights users will need to consider when validating their PGx workflow for all possible star alleles and options you have for automating your PGx analysis for large number of samples. Please join us for a session dedicated to the application of star allele genotyping and subsequent PGx workflows in our VarSeq software.
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Giloy, also known as Guduchi or Amrita in classical Ayurvedic texts, is a revered herb renowned for its myriad health benefits. It is categorized as a Rasayana, meaning it has rejuvenating properties that enhance vitality and longevity. Giloy is celebrated for its ability to boost the immune system, detoxify the body, and promote overall wellness. Its anti-inflammatory, antipyretic, and antioxidant properties make it a staple in managing conditions like fever, diabetes, and stress. The versatility and efficacy of Giloy in supporting health naturally highlight its importance in Ayurveda. At Planet Ayurveda, we provide a comprehensive range of health services and 100% herbal supplements that harness the power of natural ingredients like Giloy. Our products are globally available and affordable, ensuring that everyone can benefit from the ancient wisdom of Ayurveda. If you or your loved ones are dealing with health issues, contact Planet Ayurveda at 01725214040 to book an online video consultation with our professional doctors. Let us help you achieve optimal health and wellness naturally.
Spontaneous Bacterial Peritonitis - Pathogenesis , Clinical Features & Manage...Jim Jacob Roy
In this presentation , SBP ( spontaneous bacterial peritonitis ) , which is a common complication in patients with cirrhosis and ascites is described in detail.
The reference for this presentation is Sleisenger and Fordtran's Gastrointestinal and Liver Disease Textbook ( 11th edition ).
1. • There is a outbreak of endopthalmitis in
patients undergone surgery in the camp held
by District hospital
• how will you investigate?
• Which study design will you used investigate?
4. Case Control Study
Dr Suvarna Joshi
Associate Professor Microbiology
Grant Govt Medical College & JJ group
of hospitals Mumbai
5. SLO
• Indications
• Layouts of typical case control study
• Steps
• Interpretation of odds ratio & other statistics
emerging out of case control study
• Possible biases and their resolution
• Comparison with cohort studies
6. Indications
• Investigating outbreak
• Evaluating effectiveness of new vaccine
• Evaluation of treatment & program efficacy
• Genetic epidemiology
• Occupational health research
• Evaluation of screening
• Outbreak investigations
8. General characteristics
• Observational epidemiological study
• Analytical type
• Testing hype
• Hypothesis – association type
• Two groups-case , control
• Retrospective –
going back from outcome(disease) to exposure
• Also called Flashback study
9. Steps
• Sample size estimation
• Selection of cases
• Control matching
• Collection of data
• Applying statistics
10. Selection of cases
Definition of cases
• Individuals with the disease entity under
investigation (as per standard definition)
• Based on standard diagnostic criteria
• These criteria should be
objective, valid, reproducible
11. Selection of Cases
• Source-
Hospital , workplace, community/general
population
Time (eligibility)-
New cases- incident cases within specified
time
Old cases- prevalent cases -derived from
cross sectional survey
Selection usually done from the available cases
12. Selection of controls
• Control- One who does not have disease
under investigation
• Need not be healthy
• Control and cases should be from same study
base(source) if cases selected from hospital
then controls also from same hospital
13. Sources for Control
• Hospital, relatives, neighbors, occupational
associates, general population
d) Neighbors
(i) walk (door to door)
(ii) Phone (random digit dialing)
(iii) Letter carrier routes
e) Friends or associates of cases
f) Siblings, spouses or other relatives
g) Other
14. Matching
• Done for confounding factors to ensure the
comparability
• Eg age, sex, occupation, education, social
status
• Individual/frequency matching
• Overmatching: do not match for risk factor
under study
• Increase power of study; increasing no. of
controls per case
15. Matching…
• Control >4 per case will just increase the cost
• Disadvantage of matching
• Time consuming
• Costly
• Exact match may not be found
• Multiple controls per case
• (one from hospital and one from general
population per case)
17. Recall bias
• eg A case control study on adults which
gathered information relating to
hospitalization prior to the age of 16 was
concerned about poor recall
• Recall bias (cases may remember
their exposure with a higher or
lower accuracy than controls do)
18. Overcoming recall bias
• In subsample of both cases and controls,
medical records were examined to determine
evidence of for difference in recall between
cases and control
19. Selection bias
• Case control study on duodenal ulcer and
smoking
• Cases- patients attending gastroenterology
clinic (likely to be severe cases)
• Any risk factor derived from those cases may
represent risk factors for severity rather than
ulcer susceptibility per se
• Referal practice
20. Information/interviewer’s bias
• Case control study on possible link between
febrile illness and subsequent early pregnancy
loss
• Greater care in introducing questions to the case
mothers, the study coordinator was concerned
that the interviewer might have probed more
closely for history of fever in the cases
• It was found that interviewer was taking 10 min
more than normal pregnant controls
21. Case Control Design
Time
Direction of Inquiry
Population
Cases with
the Disease
Controls without
the disease
Exposed
Exposed
Not Exposed
Not Exposed
22. Case-Control Studies: Methodology
Then measure,
post-exposure
First Select the Cases
and Controls
Cases
(with
disease)
Control
(without
disease)
Were Exposed A B
Not Exposed C D
A+C B+D
Population
Exposed
A/A+C B./B+D
23. Figure 1 (continued)
a
c ad
Odds Ratio = =
b bc
d
Risk = a
a + b
= c
c + d
a b
c d
Case Control
E+
E-
24. Kidney stone
present
Kidney stone
absent
Total
Drinking hard
water
90 (a) 20 (b) 110
Not drinking
hard water
10 (c) 80 (d) 90
total 100 100 200
Exposure rate in cases = a/a+c = 90/90+10= 90%
Exposure rate in control = b/+d= 20/20+80= 20%
Odds ratio= ad/bc = 90x80/20x10=7200/200=36
25. • Odd ‘s ratio =1 no association
• > 1 positive association
• < 1 protective effect
26. Strength of Association
Relative Risk;(Prevalence); Odds Ratio Strength of Association
0.83-1.00 1.0-1.2 None
0.67-0.83 1.2-1.5 Weak
0.33-0.67 1.5-3.0 Moderate
0.10-0.33 3.0-10.00 Strong
<0.01 >10.0 Approaching
Infinity
27. Nested Case-Control Studies
Figure 3
Study Population
TIME 1
YEARS
TIME 2
Develop
Disease
Do Not
Develop
Disease
CASES CONTROLS
CASE-CONTROL STUDY
Obtain
interviews,
bloods,
urines, etc.
28. A. Advantages of Nested Case-Control Studies
1. Possibility of recall bias is eliminated, since data
on exposure are obtained before disease
develops.
2. Exposure data are more likely to represent the
pre-illness state since they are obtained years
before clinical illness is diagnosed.
3. Costs are reduced compared to those of a
prospective study, since laboratory tests need to
be done only on specimens from subjects who
are later chosen as cases or as controls.
29.
30. • A major limitation of cross-sectional surveys
and case-control studies is difficulty in
determining if exposure or risk factor
preceded the disease or outcome.
to overcome this problem ?
32. WHAT IS COHORT
• Ancient Roman military
unit, A band of warriors.
• Persons banded
together.
• Group of persons with a
common statistical
characteristic. [Latin]
• E.g. age, birth date,
33. Indication
• When a good evidence of association between
exposure and disease
• When exposure is rare but incidence of
disease in exposed is high
• When follow up is easy and cohort is relatively
stable
• Ample funds available
34. Elements of cohort study
• Selection of study subjects
• Obtaining data on exposure
• Selection of comparison group
• Follow up
• Analysis
35. Selection of subject
• Group of people exposed to suspected cause
• Eg cohort group who drink hard water (study
cohort)
• And cohort who don’t drink hard
water(control cohort)
• Comparison group are in built based on
gradation of exposure
36. • Cohort must be free from disease under study
• Both cohort should be equally susceptible to
the disease under study
• Both cohort should be comparable
• Diagnostic & eligibility criteria must be
defined before study commences
37. Characteristic of Cohort study
Longitudinal
Prospective studies
Forward looking study
Incidence study
starts with people free of disease
assesses exposure at “baseline”
assesses disease status at “follow-up”
38.
39. b+d
Frame work of Cohort studies
c
c+d
a
a+b
Total Yes
Disease Status
Yes
No
Exposure
Status
b
d
a+c
N
No
Study
cohort
Comparison
cohort
40. Selection of study subjects
• General population
– Whole population in an area
– A representative sample
• Special group of population
– Select group
• occupation group / professional group (Dolls study )
– Exposure groups
• Person having exposure to some physical, chemical or biological
agent
– e.g. X-ray exposure to radiologists
41. Obtaining data on exposure
• Personal interviews / mailed questionnaire
• Reviews of records
– Dose of drug, radiation, type of surgery etc
• Medical examination or special test
– Blood pressure, serum cholesterol
• Environmental survey
• By obtaining the data of exposure we can classify
cohorts as
– Exposed and non exposed and
– By degree exposure we can sub classify cohorts
42. Selection of comparison group
• Internal comparison
– Only one cohort involved in study
– Sub classified and internal comparison done
• External comparison
– More than one cohort in the study for the purpose of
comparison
– e.g. Cohort of radiologist compared with ophthalmologists
• Comparison with general population rates
– If no comparison group is available we can compare the
rates of study cohort with general population.
– Cancer rate of uranium miners with cancer in general
population
43. Follow-up
• To obtain data about outcome to be determined
(morbidity or death)
– Mailed questionnaire, telephone calls, personal interviews
– Periodic medical examination
– Reviewing records
– Surveillance of death records
– Follow up is the most critical part of the study
• Some loss to follow up is inevitable due to death
change of address, migration, change of occupation.
• Loss to follow-up is one of the draw-back of the
cohort study.
47. Estimation of risk
• Relative Risk
incidence of disease among exposed
RR = ______________________________
Incidence of disease among non-exposed
a/a+b
= _________
c/c+d
48. Estimation of Risk
• Attributable Risk
Incidence of disease among exposed –
incidence of disease among non exposed
AR = _______________________________
Incidence of disease among exposed
a/a+b – c/c+d
AR = _______________
a/a+b
49. Smoking Lung cancer Total
YES NO
YES 70 6930 7000
NO 3 2997 3000
73 9927 10000
Find out RR and AR for above data
50. • Incidence of lung cancer among smokers
70/7000 = 10 per 1000
• Incidence of lung cancer among non-smokers
3/3000 = 1 per thousand
RR = 10 / 1 = 10
(lung cancer is 10 times more common among
smokers than non smokers)
AR = 10 – 1 / 10 X 100
= 90 %
(90% of the cases of lung cancer among smokers are
attributed to their habit of smoking)
51. Types of Cohort Study
• Prospective cohort study
• Retrospective (historical) cohort study
• Combination of Retrospective and Prospective
cohort study.
52. Cohort studies
Strengths
• We can find out
incidence rate and risk
• More than one disease
related to single
exposure
• can establish cause -
effect
• good when exposure is
rare
• minimizes selection and
information bias
Weaknesses
• losses to follow-up
• often requires large
sample
• ineffective for rare
diseases
• long time to complete
• expensive
• Ethical issues
53. Comparison between Case control & Cohort
Case control
• Proceed from effect to
cause
• Involves few subjects
,quick ,less expensive
• Yields only estimate of
relative risk by virtue of
odds ratio
• Sampling bias
• Measuremnet bias
Cohort
• Proceed from cause to
effect
• Involves large no. prolong
duration, expensive
• Yield incidence
rate,relative risk,
attributable risk
• No sampling bias
• No information bias