epidemiology Flashcards
epidemiology
the study of distribution, frequency & determinants of health-related (diseases or conditions) events in populations
what is epidemiology used for?
the application of this study is to control health problems
Science of Public Health
Epidemiology
Features of epidemiology
its for epidemics
surveillance of population health status
tracks disease outbreaks
defines health risks
assesses risk factors for chronic diseases
epidemiological inquiry: what is being tracked?
case counts
who what where?
are there commonalities between who is catching the disease?
are there risk factors that make someone more prone to catching this disease?
health-related Events and outcomes
death
injury
disease
what happens when there’s intervention? (vaccines)
risk factors
Steps of studying disease
scientific method
hypothesis
observation to collect data, watch the disease, and do experiments
analyze and assess
Distribution of disease
time
place
who’s affected?
Determinants
factors that effect health
Four determinants
Biological
social
cultural
environmental
assessment
Assessment: This involves collecting and analyzing data to identify health problems and their underlying causes.
policy development
Developing strategies to reduce effects of negative factors or increase effect of positive factors
assurance
Implementation of programs or interventions to address specific factors
Who is involved in surveillance
citizens
local & state health departments
CDC
Case definition
A case definition is a set of criteria used to define a particular health condition or disease
Counting cases
helps track the occurrence and spread of diseases and other health conditions within populations
epidemic curve
An epidemic curve is a graphical representation of the distribution of cases of a disease or condition over time.
burden of disease: consequences
The burden of disease refers to the impact that a particular health condition or disease has on a population, often measured in terms of morbidity (illness) or mortality (death) rates.
ex: death, disability, economic impact, health disparities etc.
epidemic models
Epidemic models are mathematical models that are used to simulate the spread of infectious diseases within populations
Chain of Infection
The chain of infection is a model that describes the series of events that must occur for an infection to spread from a reservoir (the source of the infectious agent) to a susceptible host.
Consists of an infectious agent, a reservoir, a portal of exit, a mode of transmission, a portal of entry, and a susceptible host, which together allow for the spread of infection.
Contact Tracing
Contact tracing is a public health strategy that involves identifying, locating, and monitoring individuals who have come into contact with an infected person in order to prevent further spread of a contagious disease.
Chart abstraction
Chart abstraction is a method used to collect data from medical records or other sources by systematically reviewing and extracting relevant information.
This may involve reviewing a patient’s medical history, laboratory results, imaging studies, or other documentation in order to collect data for research, quality improvement, or other purposes
incidence
The number of new cases of a disease or condition within a defined population over a specific period of time.
prevalence
The total number of cases of a disease or condition within a defined population at a specific point in time.
hospitalizations
The number of individuals who are admitted to a hospital for treatment of a particular disease or condition.
hospitalizations
The number of individuals who are admitted to a hospital for treatment of a particular disease or condition.
deaths
The number of individuals who have died as a result of a particular disease or condition.
Epidemic Curve
A graphic representation of the number of new cases of a disease or condition over time
CDC
The CDC provides guidance and support to state and local health departments, conducts research on disease and injury prevention, and serves as a source of health information for the public.
National Notifiable Diseases Surveillance System (NNDSS)
A national surveillance system in the United States that collects and analyzes information on cases of diseases that are considered to be of public health importance and are required by law to be reported to public health authorities.
Center for Health Statistics:
A division of the National Center for Health Statistics (NCHS) that collects and analyzes health data to inform public health policy and research.
What are some of the leading causes of mortality?
heart disease, cancer, COVID, unintentional injuries, diabetes,
examples of past epidemics
Cholera, AIDs, Influenza, SARS, Hep A, Shigella
Eosinophilia-Myalgia Syndrome
rare but serious medical condition. Severe muscle pain, along with eosinophilia, which is an abnormally high number of eosinophils, a type of white blood cell, in the blood.
What caused the cases of EMS?
All 3 cases took L-tryprophan:
batch of L-tryptophan produced by a Japanese company was found to be contaminated with impurities that were later linked to cases of EMS.
summary of the EMS problem:
The New Mexico State Health Department interviewed 12 patients who had used L-tryptophan and found a link between the supplement and the illness.
They also interviewed healthy individuals from the same area and found that only two of them had used L-tryptophan.
This information helped establish that L-tryptophan use was associated with the outbreak of illness.
The CDC was notified and identified 243 possible cases across 35 states.
The FDA issued a recall of L-tryptophan, and a change in manufacturing was made to remove the toxic substance.
Framingham Heart Study
5000 people were followed over 10 years and monitored with physical exams, medical histories & lifestyle factors were all considered
Cohort design
healthy people were tracked over time
Longitudinal
repeated observations over a long period of time
prospective
designed to follow participants going forward in time, from the present into the future
Major risk factors for heart disease
Identified through the study, include:
high blood pressure
high cholesterol
smoking
weight gain
lack of exercise
outcomes of the study
60% decrease in death rate from heart rate between 1950-1970
This suggests that there was a significant improvement in overall health and a reduction in mortality over the course of the study.
neurological evaluations
In 1978, neurological evaluations were added to the study to assess the incidence and risk factors for stroke and dementia.
offspring study
followed the children of the original participants to examine the genetic and environmental factors associated with cardiovascular disease and other health outcomes in subsequent generations.
Jackson Heart Study
Follow 5000 black residents in Mississippi
monitored risk factors & health of these residents
ex: smoking, accesss to healthcare, discrimination
Goal?
to gain information to stop the epidemic of heart diseases In the African American community
women’s health initiative
NIH funded (national institute of health)
HRT Therapy
HRT was believed to reduce the risk of osteoporosis, heart disease, and other health problems that can occur after menopause.
Duration & results of women’s study
8 years
no effect of HRT noted
goals of WHI?
The goal of the study was to examine other factors that could affect women’s health–including a low-fat diet and risks for breast and colorectal cancer, as well as cardiovascular disease
Cancer risk factors
became a disease of interest due to an increase in mortality rate of lung cancer
risk factors:
smoking
air pollution
Doll and Hill Study
Followed British physicians
Prospective (future), longitudinal (over a long period of time)
Followed all types: smokers, non & ex
causes of death were registered
happened over 20 years
Conclusions: Doll and Hill
Mortality rate was 20x higher in smokers than non smokers
the more someone smoked the more likely they were to die
heart attack were higher with smokers
interesting conclusions: smokers Doll and Hill
death rate with ex-smokers decreased as the time between them smoking increased
Hammond and Horn
188,000 men
deaths were taken from their death certificates
confirmed Doll and Hill smoking study
Results of Hammond and Horn
Smokers also more likely to die from cancer of mouth, pharynx, larynx, esophagus
Heavy smokers 2.4X more likely to die of heart disease than non-smokers
