What are the 7 uses of epidemiology?
What are secular trends and what are they used in?
Changes in disease frequency over time. They're used in historical use of epidemiology health and illness.
Name and describe the factors affecting changes in trends?
1. Aging of the general population: because of improved medical care, the impact of mortality from diseases reduces. There may be greater uncertainty about the precise cause of death.
2. Changes in diagnostic criteria/reporting: criteria changes over time due to increased knowledge about a disease, some categories of diseases used earlier in time may be omitted altogether.
3. Changes in disease treatment and cure: disappearing disorders, residual disorders, persisting disorders, new epidemics.
4. Changes in population dynamics (migration): a) births, b) deaths, c) migration. When these factors don't contribute to net increases or decreases, the population is in equilibrium.
Define these terms:
- fixed population
- dynamic population
- steady population
Fixed population: adds no new members --> decreases in size due to only having deaths.
Dynamic population: adds new members through migration and births or loses through emigration or death.
Steady population: in a steady state when the number of members exiting equals the number entering.
What does yellow, green and red mean in terms of population size?
Name some demographic and social variables that might describe a healthy community.
Name some variables related to community infrastructure that might describe a healthy community.
Name some health-related outcome variables that might describe a healthy community.
Describe how age and sex distribution affect the health of a community.
In a community that has primarily elderly, health problems related to aging would tend to predominate. Because of the longer life expectancy of women, an older population would tend to have a majority of elderly women, who might have unique health needs. Point is, age and sex of the population have specific needs that the community will need to cater to create a healthy one.
Describe how socioeconomic status affect the health of a community.
People who have inadequate income and job opportunities lack health insurance and access to health care. This also includes people who have low educational attainment, meaning the population will be less aware of dietary and exercise practices that promote health.
Describe how racial, ethnic and religion of a population affect the health of a community.
Some health outcomes are just more common in one racial or ethnic group. Ex. diabetes and latinos and sickle cell anemia and african americans. Members of some religions may adopt specific lifestyles. Ex. abstaining from alcohol.
What does it mean to get rid of health disparities?
To eliminate health disparities among segments of the population, including differences that occur by gender, race or ethnicity or income.
What are health disparities?
Differences in health outcomes that are closely linked with social, economic and environmental disadvantage.
What are the six areas of health disparities, describe them.
Regarding the health of the community, epidemiology not only is a descriptive tool, but also plays a role in policy evaluation. True or false?
True; p. 228.
Part of the reason for skepticism about epidemiologic research is the inability to "prove" anything. True or false?
True; p. 240.
What is causality?
Showing the relationship and identifying the etiologic (causal) associations between an exposure and an outcome.
What is a cause?
An event, condition or characteristic that preceded the disease and without the disease event either wouldn't have occurred or wouldn't have occurred until some other time.
What is the criteria of Koch's postulate for causation?
1. The agent is always found in every case of the disease.
2.The organism is not with any other disease; one agent-one disease.
3. The organism isolated from someone who has the disease, and cultured through several generations produces the disease in a healthy animal.
Name the criteria Sir Austin Bradford Hill created for causation.
Describe Bradford-Hill's strength of association criteria for causation.
The stronger the association, the more likely of a causal relationship. It's less likely to be the result of errors.
Weak associations disprove causation. True or false?
False; weak associations do not disprove causation.
Describe Bradford-Hill's consistency upon repetition criteria for causation.
This refers to whether the association between an agent and health effect has been observed by different persons, in different places, circumstances and times.
Describe Bradford-Hill's specificity criteria for causation.
The causal factor should lead to only one disease and that the disease should result from this single cause. However, lack of specificity is not reason to refute causation.
Describe Bradford-Hill's time sequence/temporal relationship criteria for causation.
The exposure to the causal factor must precede the onset of disease. This can be hard to prove.
Describe Bradford-Hill's biological criteria for causation.
This shows an evidence of a dose-response curve. Meaning that an increase in level, intensity and duration to an agent leads to progressive increases in risk.
Describe Bradford-Hill's plausibility criteria for causation.
The association needs to be plausible with known biological facts about the disease (e.g. chemicals in cigarettes harm lung tissue). Common sense and known biology must take precedence over statistical relationships.
Describe Bradford-Hill's coherence of explanation criteria for causation.
The association must no seriously conflict with what's already known about the natural history and biology of the disease.
Describe Bradford-Hill's experiment criteria for causation.
Experiment has to be randomized as it's the only way that can claim causality.
Describe Bradford-Hill's analogy criteria for causation.
That if one agent can cause "outcome X", so might others. Not as strong as the other criteria.
What were the five criteria for causality before Bradford-Hill.
Association does not equal causation. True or false?
True.
What are risk factors?
A risk factor is an exposure that is associated with a disease or health outcome.
What are the 3 criteria for risk factors?
Name some studies that estimates the risks to individuals?
- case control
- cohort study
What is a case-control design?
Design that compares persons with a disease (cases) against those without it (controls). This is an observational study.
What is a cohort design?
Design where a group of people free from a disease is assembled according to a variety of exposure that are hypothesized to increase/decrease the chance of getting a disease.