4.Patterns of Health and Disease Flashcards
Epidemiology
- The science of population health
- study of the distribution and the determinants of health-related states
- detective stories or The study of what is upon the people
Contributions of Epidemiology
Identification of risk factors
Pinpoint modifiable risk factors
Lifestyle changes
Public health changes
Study the distribution of disorder in the community
Epidemiologic Triad
Agent – the disease / organism
Host – the population
Environment – the community, physical/biological/economic/political/social
Person–Place–Time model
investigators examine characteristics of the persons affected (the host in the triangle model), the place (environment) or location, and the time period involved (which could relate to the agent, host, or environment).
The Haddon Matrix
- two-dimensional phase-factor matrix
- first dimension comprises the three factors influencing injury: host, agent, and environment
physical/biological/economic/political/social - second dimension is the injury phase divided into pre-event, event, and post-event
we can analyze an injury event by the influencing
factors over time, which makes it possible to identify factors related to the host,
agent, and environment within the phases before, during, and after the event
that might be explanatory and contribute to injury prevention strategies
Web of causation model
One factor leads to others, which leads to others. All factors interact with each other to produce the health outcome.
The whole is greater than the sum of its parts.
Criteria for Determining Causation
The association is strong
Consistency with other knowledge
The association is temporally correct
Dose–response relationship
Consideration of other alternative explanations
The association is biologically plausible
Replication of findings
Cessation of exposure
The association is specific
4 levels of pprevention
Primordial
Primary
Secondary
Tertiary
primordial prevention
prevention of risk factors for disease from existing
ex. remove access to tobacco products and environmental tobacco smoke from public venues
Morbidity
you have the thing
Mortality
you die from it
Incidence
1 event. All the people who are newly diagnosed. The rate of how fast people are added.
the number of instances or new events of a disease in a defined population within a given period of time
Prevalence
is over time. All the people who’ve had it, not just the new cases
the total number of persons in the population who have the condition at a particular time
Examples of Internal & External risk factors
Internal risk factors
Age, race, sex
External risk factors
Virus, pollutant
Attributable risk
- The incidence rate in the exposed group minus the incidence rate in the nonexposed group
- It is a measure of the absolute effect of exposure by removing the amount of disease that would have occurred anyway.
You are asked to determine the number of patients with active cases of the flu in a long-term care setting on February 9, 2015. This is an example of:
- Rates
- Incidence
- Prevalence
- Data collection
- Statistics
C. Prevalence
The prevalence of a disease or condition refers to the total number of people in the population who have the condition at a particular time. Thus, prevalence may be calculated in a “one-shot” cross-sectional (“slice of time”) or retrospective (backward looking) study.
Sources of Community Health Data
Census
Vital statistics
Notifiable disease reports
Medical and hospital records
Social welfare reports
Sensitivity
how often does it correctly identify people that DO have it
is the ability to correctly identify individuals who have the disease—that is to identify a true positive. A test with high sensitivity will have few false negatives
- high sensitivity, that is, a low rate of false negatives (people who have the disease but are not detected by the screening test).
Specificity
how often does it correctly identify people that DON’T have it
is the ability to correctly identify individuals who do not have the disease or to call a true negative “negative.” A test with high specificity has few false positives
low specificity means that you will have a high number of people who do not have the disease but whom the test identifies as having it (false positives). Using such a test will alarm many people needlessly and will cause unnecessary
Is the following statement True or False?
As sensitivity increases, specificity decreases, and vice versa
True
There is an inverse relationship between sensitivity and specificity; it is not possible to have a test with both 100% specificity and sensitivity.
