This document discusses and compares case-control and cohort studies in epidemiology. It defines epidemiology as the study of health-related states in populations and applying this to control health problems. Analytical epidemiology focuses on testing hypotheses about individuals within populations. Both case-control and cohort studies are described as types of analytical epidemiology. Case-control studies are retrospective while cohort studies are prospective. The key differences and advantages/disadvantages of each study type are outlined.
This document discusses and compares case-control and cohort studies in epidemiology. It defines epidemiology as the study of health-related states in populations and applying this to control health problems. Analytical epidemiology focuses on testing hypotheses about individuals within populations. Both case-control and cohort studies are described as types of analytical epidemiology. Case-control studies are retrospective while cohort studies are prospective. The key differences and advantages/disadvantages of each study type are outlined.
Descriptive and Analytical Epidemiology coolboy101pk
This document provides an overview of a training session on descriptive and analytic epidemiology. Descriptive epidemiology involves describing disease frequency, distribution, and determinants in populations using measures like prevalence and incidence. Analytic epidemiology aims to understand why diseases occur using study designs like cohort studies and case-control studies to test hypotheses. Key terms discussed include measures of association like relative risk and odds ratio, and statistical tests like confidence intervals and p-values.
This document provides an overview of descriptive epidemiology. Descriptive epidemiology involves studying the distribution and determinants of health-related states or events in specified populations, without comparing groups. The main objectives are to describe the incidence, prevalence, and natural history of diseases and their distribution according to person, place and time. Descriptive studies make hypotheses about potential causes, but do not confirm them due to the lack of a comparison group. Key steps include defining the population and disease, describing disease distribution by time, place and person, measuring disease occurrence, comparing to known indices, and formulating etiological hypotheses.
Epidemiology is the study of how diseases are distributed in populations and the factors that influence this. It examines why some people develop illnesses and others do not. Epidemiology helps public health officials understand health problems in communities and find ways to control and prevent diseases. The history of epidemiology shows how early physicians like Hippocrates linked environmental factors to health, and later scientists such as John Snow used epidemiological findings to control outbreaks. Modern epidemiology involves counting cases, measuring populations, analyzing health problems, applying solutions, and evaluating their effectiveness. It provides insights used in public health programs and patient care.
This document discusses case control studies and provides examples to illustrate their use. It defines a case control study as an epidemiological approach that starts with identified "cases" who have a disease and compares them to "controls" who do not have the disease. The study then examines past exposure history to identify potential risk factors.
Key aspects of case control studies covered include selecting appropriate cases and controls, matching on important variables, measuring past exposure, calculating odds ratios to estimate disease risk associated with exposures, and potential biases like selection bias, recall bias, and survivorship bias. Examples are provided of early case control studies that helped identify links between smoking and lung cancer, and between rubella infection and cataracts.
This document provides information on epidemiological study designs, including analytical studies, case-control studies, and cohort studies. It defines epidemiology as the study of health-related states in populations. Case-control studies look backward from the outcome to exposures, comparing cases to controls. Cohort studies follow groups over time to examine exposure-outcome relationships. The key difference is that cohort studies measure incidence while case-control studies measure odds ratios. Selection of appropriate study populations and controls is important to minimize biases.
The document provides an overview of a presentation on types of research given by Manoj Patel. It defines research and lists its main objectives as extending knowledge, revealing hidden facts, generalizing laws, and verifying existing theories and facts. The presentation then describes several common types of research, including descriptive and analytical research, applied and fundamental research, quantitative and qualitative research, conceptual and empirical research, and others. It provides examples to illustrate the differences between each type.
This document outlines the key concepts and components of research. It defines research as the systematic study of trends or events through careful data collection, analysis, and interpretation. Some key points discussed include:
- The characteristics of good research, which include being empirical, logical, analytical, critical, and methodical.
- The qualities of a good researcher, such as being resourceful, creative, honest, and religious.
- The values of research to humanity, such as improving quality of life, instruction, and satisfying needs through new discoveries and applications.
- The different types of research like basic, applied, and developmental research.
- How research classifications include library, field, and laboratory research.
Research is the systematic and objective analysis and recording of controlled observations that may lead to the development of generalizations, principles, or theories, resulting in prediction and possible control of events .
This document provides an overview of key concepts in research methodology, including:
1. It defines research as an organized and systematic process of finding answers to questions through a defined set of steps and procedures.
2. It discusses different types of research including quantitative, qualitative, basic, applied, longitudinal, descriptive, classification, comparative, exploratory, explanatory, causal, theory testing, and theory building research.
3. It also discusses alternatives to research-based knowledge such as relying on authority, tradition, common sense, media, and personal experience.
The document discusses various types of research including applied research, basic research, correlational research, descriptive research, ethnographic research, experimental research, and exploratory research. Applied research seeks practical solutions to problems, while basic research expands knowledge without a direct application. Correlational research examines relationships between variables without determining cause and effect. Descriptive research provides accurate portrayals of characteristics, and ethnographic research involves in-depth study of cultures. Experimental research establishes cause-and-effect through controlled manipulation of variables.
A Guide to SlideShare Analytics - Excerpts from Hubspot's Step by Step Guide ...SlideShare
This document provides a summary of the analytics available through SlideShare for monitoring the performance of presentations. It outlines the key metrics that can be viewed such as total views, actions, and traffic sources over different time periods. The analytics help users identify topics and presentation styles that resonate best with audiences based on view and engagement numbers. They also allow users to calculate important metrics like view-to-contact conversion rates. Regular review of the analytics insights helps users improve future presentations and marketing strategies.
The document discusses different sources of public health data including population censuses, vital statistics, routine health records, surveillance data, and sample surveys. It provides details on population censuses, vital statistics like birth and death certificates, death registration systems, what can be learned from birth and death data, other death statistics, surveys, and sources of morbidity data like disease registries and hospital records. The sources of data are important for understanding population health trends, birth and death rates, cause of death, mortality rates, and disease incidence.
- The document discusses factors to consider when determining sample size, such as objectives, sampling design, required accuracy, population variability, and practical constraints.
- It provides formulas for calculating sample sizes for different study designs, including simple random sampling, stratified sampling, and hypothesis testing of one or two proportions/means.
- An example calculates the needed sample size of 152 people in each group to test the hypothesis that drug A affects blood pressure, based on parameters from a pilot study.
This document contains a questionnaire with structured, less structured, and unstructured questions about various health-related topics. The structured questions include dichotomous choice and multiple choice questions about gender, risk factors for heart disease, and computer usage. The less structured questions use Likert scales to assess attitudes toward abortion and exercise regardless of weather. Semantic differentials are used to rate opinions of smokeless tobacco and feelings during a test. Unstructured questions include short answer and essay questions about exercise habits, diet, advantages of worksite health programs, proper lifting technique, and differences between aerobic and anaerobic exercise.
9. วิถีทางในการวิจัยทางการแพทย์ ขั้นตอน วิธีการ ผลที่ได้ 1. แจกแจงปัญหา Cross sectional study Descriptive study 2. ตั้งสมมติฐาน Longitudinal study อธิบายลักษณะการเกิด โรค สร้างสมมติฐาน 3. พิสูจน์ว่าปัจจัยมีผล Cohort study Analytic study ต่อการเกิดโรค Case-control study อธิบายต้นเหตุและ ปัจจัย 4. พิสูจน์ต้นเหตุของโรค 5. ทดลอง รักษา ควบคุม Experimental study Clinical study หรือป้องกัน (Intervention study) การนำมาใช้ในคลินิก อธิบายผลการรักษา ป้องกัน ควบคุม
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12. Case-control study ( 2 ) อดีต ปัจจุบัน Case Control Exposed Exposed Non exposed Non exposed Studied population Cause Effect
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19. Cohort study ( 2 ) ปัจจุบัน อนาคต Studied population (No disease) Exposed Non exposed Disease Disease No disease No disease Cause Effect
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25. Does HIV infection increase risk of developing TB among drug users? EPIET ( www )
26. Person-years Cases Smoke 102,600 133 Do not smoke 42,800 3 Presentation of cohort data: Person-years at risk Tobacco smoking and lung cancer, England & Wales, 1951 Source: Doll & Hill EPIET ( www )
32. Sources of Error in Epidemiologic Studies Random error Bias Confounding Effect Modification Reverse Causation
33. Sources of Error in Epidemiologic Studies Random error Large sample size, replication Bias Be careful Confounding Effect Modification Reverse Causation
34. Confounding can be controlled by: - Randomization: assures equal distribution of confounders between study and control groups - Restriction : subjects are restricted by the levels of a known confounder - Matching : potential confounding factors are kept equal between the study groups - Stratification for various levels of potential confounders - Multivariable analysis (does not control for effect modification )
35. Effect modification can be assessed by: - Stratification for various levels of potential confounders - Multivariable analysis (by assessing interaction) More importantly, NOT by adjustment in multivariable analysis Reverse causation can be assessed by: - Mendelian randomization
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38. Case-control study structure time CASES Adults with Heart failure that develops before age 50 CONTROLS Adults (18-50) without heart failure RISK FACTORS Demographic Behavioral Biological Genetic present
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40. Hypertension early in life is a risk factor for heart failure before age 50 among blacks