NUR 412 Epi
what is incidence?
# of new cases of a particular condition identified during a specified time period divided by the total population at risk during that time period [NEWLY SICK]
Research process for an epidemiologic study
(1) Identify the problem. (2) Review the literature. (3) Design the study. (4) Collect the data. (5) Analyze the findings. (6) Develop conclusions and applications. (7) Disseminate the findings.
1.5 relative risk is what percentage more at risk
50%
Rates of occurence:
Any statistical measures expressing the proportion of people w/ a given health problem among a population at risk (where the numerator is a subset of the denominator) Why they matter? They show the extent of a problem and allow comparison between groups of different sizes
examples of descriptive epidemiology
Case reports, Case series, Cross-sectional studies, & Ecological studies
examples of analytic epidemiology
Case-control studies (proves association) Cohort studies (proves temporality)
epidemiology is a discipline that...
Describes, quantifies, & postulates causal mechanisms for disease & health in populations Develops methods for the control of diseases
Epidemiologic studies are of three general types →
Descriptive: 1st we seek to understand & hypothesize Analytic: 2nd we seek to test hypotheses & determine cause Experimental: Analytical in nature, but involves manipulation
second disease status
Determine the exposure status of those with & without disease
what is replication?
Do studies by different groups consistently arrive at the same findings? You want to see across studies same relationships
Eco-epidemiology
Focus on people's behaviors based on environmental factors Broaden knowledge and acknowledging the determinants of health into account
first disease status
Identify those with a disease & those without the disease
what is descriptive epidemiology
Investigations that seek to observe & describe patterns of health-related conditions that occur naturally in a population
who is the father of epidemiology?
John snow
Sanitary statistics, what is the paradigm, analytic approach, and prevention approach?
Miasma: poisoning from foul emanations Analytic approach: clustering of morbidity and mortality Prevention approach: drainage, sewage, sanitation
PERIE
Problem Etiology Recommendations Implementation Evaluation
analytic epidemiology
Seeks to identify associations between a particular disease or health problem & its possible causes
what is analogy?
Similarities between the association of interest & others → Like effects imply like causes
JOHN SNOW'S MAPPING OF CHOLERA DEATHS LED HIM TO IDENTIFY what...?
THE SOURCE OF THE PROBLEM
Coherence of Explanation
The hypothesized cause does not conflict with current knowledge about the natural history or biology of the disease
Biological Plausibility
The hypothesized cause makes sense based on current biological or social models
what is risk?
The probability that a given individual will develop a specific condition or disease
what is morbidity a ratio of?
The ratio of number of cases of a condition to the number in the population at risk
Causality criteria: specificity [WEAKEST-- very simplistic]
The same cause always produces the same effect, & the same effect never arises but from the same cause
assumption of epidemiology
The spread of disease is NOT random
definition of epidemiology
The study of the distribution & determinants of health-related states or events, & the application of this study to the control of the diseases & other health problems
what is prevalence?
Total # of people affected by a particular condition at a specified time period (new + old cases) divided by the total population at risk during that time period [NEW + EXISTING ILLNESS]
what is an agent?
a factor that causes or contributes to a health problem or condition
<1 relative risk indicates what
a negative association
relative risk >1 indicates what
a positive association
what is a host?
a susceptible human or animal who harbors & nourishes an agent
When we can't satisfy all causality requirements, we can look to what?
additional supportive evidence
what is an environment?
all external factors that might influence a host's resistance or vulnerability
prevalence includes.....
all new and existing cases
what is outbreak?
an increased number of cases in the population that does not approach epidemic proportions
analytic approach: relations within and between localized structures organized in a hierarchy of levels
analysis of determinants and outcomes at different levels of organization using new information systems and biomedical techniques
prevention approach: eco-epidemiology
apply both information and biomedical technology to find leverage at efficacious levels
what are agents?
biologic, chemical, physical, nutritional
risk is directly influenced by what?
biology, lifestyle, environment, & health care
individual association
case control study
examples of mortality
cause-specific (COVID) age-specific (what we die based off of age) case-fatality (you get something but die from a complication)
analytic approach: miasma
clustering of morbidity and mortality
demonstrate temporality
cohort study
prevention approach: chronic disease epidemiology
control risk factors by modifying lifestyle (diet), agent (guns), or environment (pollution)
Mortality is a rate of occurrence that tells us about...
death
the epidemiological triad model includes what?
direct and indirect causes of disease
what is endemic?
disease that is constantly present in a particular community or region
snow's evidence:
distribution of disease
prevention approach: sanitary statistics
drainage, sewage, sanitation
group association
ecologic and cross sectional studies
altering the cause alters the effect
experimental studies + supporting evidence
Dose response relationship demonstrates what?
exposure and disease change together
Considers two main factors →
exposure and outcome
chronic disease what is the paradigm, analytic approach, and prevention approach?
exposure related to outcome risk ratio of exposure to outcome at individual level in populations control risk factors by modifying lifestyle, agent, or environment
cohort studies begin with...
exposure status
what is a risk factor?
factors that occur more frequently within the group with the disease than with a non-diseased group
As multiple causation became more apparent, the web of causation model...
gained popularity
Infectious disease epidemiology what is the paradigm, analytic approach, and prevention approach?
germ theory: single agent related to specific disease lab isolation nd culture from disease sites and experimental transmission/reproduction of lesions interrupt transmission
population at risk:
groups who have a greater potential to develop a health problem given specific contributing factors
the epidemiological triad three elements
host, agent, environment
The strength of association, demonstrates what?
how closely related the risk factor and disease
process for establishing causality
hypothesis generation (group and individual association) requirement 1: cause associated with effect (individual association) requirement 2: cause precedes effect (demonstrate temporality) requirement 3: change in cause changes effect (altering the cause alters the effect)
The distribution of disease helps us generate what?
ideas and hypotheses about causation
morbidity is a rate of occurrence that tells us about....
illness/disability/injury (living w/ illness)
if you were to prevent new cases that is what
incidence
the epidemiological triad model allows epidemiologists to map what?
interrelationships among factors contributing to development (or prevention) of a particular health condition
prevention approach: infectious disease epidemiology
interrupt transmission (vaccines, isolation, and antibiotics)
analytic approach: germ theory
laboratory isolation and culture from disease sites and experimental transmission/reproduction of lesions
risk factors:
negative influences
relative risk =1 -- indicates what
no association
primary prevention
nutrition counseling sex education smoking cessation improved housing and sanitation immunizations removal of environmental hazards
what is epidemic?
occurrence of a great number of cases of a disease than ordinarily expected in a given population
exposure related to....
outcome
what did John snow focus on?
patterns that were causing people to fall ill via asking questions and data collection
We are also interested in the distribution and course of disease including....
person, place, and time
miasma:
poisoning from foul emanations
protective factors:
positive influences
what is absolute risk? (AR)
probability that anyone in a given population will develop a particular condition
what is relative risk? (RR)
probability that someone in a group of people with a particular characteristic will develop the condition when compared to people without that characteristic
hierarchy of evidence (from best to worst)
randomized controlled trials quasi experimental studies cohort studies case control studies cross sectional studies case reports/case studies
tertiary prevention
reduce the extent and severity of a health problem to minimize disability restore or preserve function training for employment group therapy and rehabilitation food, shelter, rest/sleep, exercise health services immunizations as needed
eco epidemiology what is the paradigm, analytic approach, and prevention approach?
relations within and between localized structures organized in a hierarchy of levels analysis of determinants and outcomes at different levels of organization using new information systems and biomedical techniques apply both information and biomedical technology to find leverage at effacacious levels
analytic approach: exposure related to outcome
risk ratio of exposure to outcome at individual level in popultions
secondary prevention
screening programs - cancer, hearing, vision, HTN initiate prompt treatment arrest progression prevent associated disability
germ theory:
single agent related to specific disease
endemic would look like what?
spotted evenly across the world
primary prevention: stages
stage 1 and 2
phase 1 pre pathogenesis
stage 1: susceptibility stage 2: subclinical disease
secondary prevention: stages
stage 2-3
phase 2: pathogenesis
stage 3: clinical disease stage 4: resolution
tertiary prevention: stages
stage 4
what does pandemic look like?
super clustered in multiple areas
what does epidemic look like?
super clustered in one spot
what is environment?
temperature, humidity, altitude, crowding, housing, neighborhood, water, milk, food, radiation, pollution, noise
To prove something is causal, we must show...
temporality
A mortality rate is the ratio of what?
the number of deaths in various categories to the number of people in a given population
what is pandemic?
the simultaneous experience of extensive disease outbreaks or epidemics in several parts of the world
An association is demonstrated in what?
varying types of studies among diverse study groups
how did John snow understand the source of disease?
via mapping
