Epidemiology Flashcards
Exam 1
Epidemiology: What is it a study of
Study of the distribution and determinants of health-related states among specified populations and the application of that study to the control of health problems
Epidemiology is the science of what?
Epi = upon
Demos = people
Ology =science
Epidemiology = the science which deals with what falls upon people…..Bridge between biomedical, social and behavioral sciences
Purpose of Epidemiology:
To discover what?
Discover the agent, host, and environmental factors that affect health
Purpose of Epidemiology:
To determine what?
Determine the relative importance of causes of illness, disability, and death
Purpose of Epidemiology:
To identify what?
Identify those segments of the population that have the greatest risk from specific causes of ill health
Purpose of Epidemiology:
To recommend what?
To recommend / assist in application of / - - evaluate best interventions (preventive and therapeutic measures)
Purpose of Epidemiology:
To evaluate what?
Evaluate the effectiveness of health programs and services in improving population health
Purpose of Epidemiology:
What does epidemiology provide the foundation for?
To provide foundation for public policy
Epidemiology Key Terms:
Epidemic or outbreak: What is it?
Epidemic or outbreak: disease occurrence among a population that is in excess of what is expected in a given time and place.
Epidemiology Key Terms:
Cluster:
Cluster: group of cases in a specific time and place that might be more than expected.
Epidemiology Key Terms
Endemic:
Endemic: disease or condition present among a population at all times.
Epidemiology Key Terms
Pandemic:
Pandemic: a disease or condition that spreads across regions.
Epidemiology Key Terms
Rate:
Rate: number of cases occurring during a specific period; always dependent on the size of the population during that period.
Historical Roots of Epidemiology
Ancient time
Ancient Times: Hippocrates (460 to 375 BC)
Historical Roots of Epidemiology
Middle Ages:
1348 - Plague (Black Death)
Historical Roots of Epidemiology
18th century:
Florence Nightingale (1820 to 1910)
Historical Roots of Epidemiology
19th century:
Modern epidemiology
Historical Roots of Epidemiology
19th century: Modern epidemiology
What did it include?
Causal thinking
Sanitary statistics
Infectious-disease epidemiology
Chronic-disease epidemiology
Historical Roots of Epidemiology
Current:
Current: Eco-epidemiology
Sources of Epidemiologic Information include
Vital statistics
Census data
Reportable diseases
Disease registries
Environmental monitoring
National Center for Health Statistics Health surveys
Informal observational studies
Scientific studies
Data Sources and Collection Methods
Data Sources include:
Individual persons
Environment
Healthcare providers
Nonhealth-related sources (financial, legal)
Public Health Core Sciences
Prevention effectiveness
Epidemiology
Laboratory
Informatics
Surveillance
Host, Agent, and Environment Model
Host:
Susceptible human or animal who harbors and nourishes a disease-causing agent
Host, Agent, and Environment Model
Agent:
A factor that causes or contributes to a health problem or condition
Host, Agent, and Environment Model
Environment:
All the external factors surrounding the host that might influence vulnerability or resistance
What is the Epidemiology Triad? What does it cause?
Host
Environment
Agent
Causes illness state?
Theories of Causality in Health and Illness: What is it?
Relationship between a cause and its effect
Theories of Causality in Health and Illness
Relationship between a cause and its effect
What kind of chain is this?
Chain of causation
Causation in noninfectious disease:
Multiple causation
Theories of Causality in Health and Illness
Relationship between a cause and its effect
Causation in noninfectious disease:
environmental exposure and behavior
Theories of Causality in Health and Illness
Multiple causation
Dever’s epidemiological model also called the Web of Causation
Web of causation: there are multiple reasons someone can get into a car accident. (ex; medical reason, impaired driving, the car- inspection sticker is fake and was never inspected, people who shouldn’t be driving are driving.
Is the following statement True or False?
The current thinking of epidemiology focuses on causal thinking.
False
Rationale: Current thinking of epidemiology is termed eco-epidemiology, distinguished by transforming global health patterns and technological advances.
Immunity: What is it?
A host’s ability to resist a particular infectious disease–causing agent.
Immunity:
What are the types of immunity?
Passive immunity:
Active immunity:
Cross-immunity:
Herd immunity:
Immunity:
Passive immunity?
short-term; acquired naturally or artificially
Immunity:
Active immunity: How long is it? How do you acquire?
long-term, sometimes lifelong; acquired naturally or artificially
Immunity:
Cross-immunity:
Cross-immunity: immunity to one agent providing immunity to another related agent
Immunity:
Herd immunity:
Herd immunity: immunity level present in a population group
Natural History of a Disease or Health Condition
What are the stages?
Susceptibility stage
Subclinical disease stage
Clinical disease stage
Resolution stage
Natural History of a Disease or Health Condition
What is included in the subclinical stage?
Incubation period
Induction period
Natural History of a Disease or Health Condition
What is clinical stage?
During the clinical disease stage, signs and symptoms develop, and in the early phase of this period, they may be evident only through laboratory test findings.
Natural History of a Disease or Health Condition
What is susceptibility stage?
In the susceptibility stage, the disease is not present, and individuals have not been exposed.
Natural History of a Disease or Health Condition
What is subclinical disease stage?
During the subclinical disease stage, individuals have been exposed but are asymptomatic
Natural History of a Disease or Health Condition
What is resolution stage?
During the resolution stage, the disease causes sufficient changes to produce recognizable signs and symptoms.
During which of the following stage would the community health nurse first expect to see signs of a disease via laboratory testing?
Clinical disease stage
Risk
Probability that a disease or unfavorable health condition will develop
Risk: What is it directly influenced by?
Directly influenced by biology, environment, lifestyle, and system of health care
Risk: What are risk factors considered?
Risk factors: negative influences
Risk:
Populations at risk: What is this?
Populations at risk: collection of people among whom a health problem has the possibility of developing because certain influencing factors are present or absent or because there are modifiable risk factors
Comparing Population Characteristics
What helps us compare health problems among different populations?
Rates help us compare health problems among different populations that include two or more groups who differ by a selected characteristic
Understanding Rates
What is rates the primary measurement for?
Rate—the primary measurement used to describe the occurrence (quantity) of a state of health in a specific group of people in a given time period
Understanding Rates
What helps determine the characteristics of those who are at high risk?
Measuring the magnitude or frequency of a state of health determines the characteristics of those who are at high risk.
Understanding Rates
What provides the best indicators of the probability that a specific state of health will occur?
Calculation of rates provides the best indicators of the probability that a specific state of health will occur.
Understanding Rates
Incidence:
refers to all new cases of a disease or health condition appearing during a given time
Understanding Rates
What kind of rates provide the best description of a health condition?
Specific rates calculated by person, place, and time provide the best description of a health condition.
Understanding Rates
Crude rate:
Crude rate—measurement of the occurrence of the health problem or condition being investigated in the entire population.
Understanding Rates
Adjusted rate:
Adjusted rate—statistical procedure that removes the effects of differences in the composition of a population, such as age, when comparing one with another.
Understanding Rates
Incidence rate
—measure of the probability that people without a certain condition will develop that condition over a period of time.
Understanding Rates
Prevalence rate
Prevalence rate—measures the number of people in a given population who have an existing condition at a given point in time
Types of Incidence Rates
Mortality rates:
Death rates, common incidence rates calculated for public health purposes
Types of Incidence Rates
Morbidity rate:
Rate at which a disease occurs in a population from acute to chronic illness.
Types of Incidence Rates
Incidence rate:
Incidence rate: Measure of the probability that people without a certain condition will develop that condition over a period of time
Types of Incidence Rates
Rate Formula:
(number of cases/population at risk) x 100 = Rate %
Types of Incidence Rates
Relative risk ratio:
The ratio of the incidence rate in the exposed group and the incidence rate in the nonexposed group.
Types Of Epidemiologic Studies include:
- Experimental
- Observational
Types Of Epidemiologic Studies include:
Observational studies include:
Descriptive
Analytic
Methods in Epidemiologic Investigative Process
Experimental: What occurs in this study?
Investigators control certain factors within the study from the beginning
Methods in Epidemiologic Investigative Process
Observational –> Descriptive epidemiology: What occurs
Descriptive epidemiology - Data are collected about health problems occurring among the population through public health surveillance.
The data collected include information about when the problem occurred, as well as where and who were affected (that is, time, place, and person).
Methods in Epidemiologic Investigative Process
Observational –> Analytic epidemiology : What occurs
Analytic epidemiology - Comparison between different groups to determine the role of different causative conditions or risk factors.
Descriptive and Analytic Epidemiology
DESCRIPTIVE: What kind of questions are being asked?
When was the population affected?
Where was the population affected?
Who was affected?
Descriptive and Analytic Epidemiology
ANALYTIC: What kind of questions are being asked?
How was the population affected?
Why was the population affected?
Methods in Epidemiologic Investigative Process – Analytic Studies
What kind of studies are used for Analytic epidemiology?
Cross-sectional studies
Case–control studies
Cohort studies
Study Design — Cross-Sectional (Prevalence) Study
Why are subjects selected?
Subjects are selected because they are members of a certain population subset at a certain time
Study Design — Cohort Study:
What kind of study is done?
Longitudinal (long term) study where a group of participants are followed over a long period of time
Study Design Type — Case-Control Study
How are subjected identified?
Subjects identified as having a disease or condition are compared with subjects without the same disease or condition
Is the following statement True or False?
Analytic epidemiology involves cohort studies.
True
Rationale: Analytic epidemiology attempts to identify associations between a human disease or health problem and its possible causes.
Research Process for an Epidemiologic Study
Identify the problem.
Review the literature.
Design the study.
Collect the data.
Analyze the findings.
Develop conclusions and applications.
Disseminate the findings.
Outbreak Investigation: How many steps are there?
Ten steps of outbreak investigations
Outbreak Investigation:
Ten steps of outbreak investigations
Establishing the existence of an outbreak
Preparing for fieldwork
Verifying the diagnosis
Defining and identifying cases
Using descriptive epidemiology
Developing hypotheses
Evaluating the hypotheses
Refining the hypotheses
Implementing control and prevention measures
Communicating findings
