Chapter 5 - Epidemiologic Principles & Methods Flashcards
Disease is a broad term, so what’s an easier way to define it?
Health outcome
Frequency
The number of cases
How do you yield a rate of frequency?
Number of cases / Size of population being studied or population at risk
Incidence Rate
The rate of new cases of a disease in a defined population over a defined period of time
What does the incidence rate measure?
The probability of a healthy person in said population developing that disease during that time
Prevalence Rate
The total number of cases existing in a defined population at a specific time
How are prevalence rates generally measured?
With a survey
Prevalence rates aren’t useful in epidemiologic studies… What are they useful for?
Assessing societal impact of a disease and planning for healthcare services
Distribution
3 Main Aspects:
- Who has the disease? (age, sex, race, economic status)
- When? (Is incidence increasing, decreasing or stable? –> disease trends)
- Where? (countries, states, counties… urban vs. rural)
Determinant
A factor that decisively affects stage nature or outcome of health
What are some examples of determinants?
Social, economic, or physical environments
Prospective Study
Epidemiologic study beginning in the present that monitors groups of people into the future, or they can start at a point in the past and look forward from there
Retrospective Study
Epidemiologic study that looks into the past for causes of diseases from which people currently suffer
Intervention Study
Epidemiologic experiments, usually done to test a new treatment for a disease or preventive measure
Control Group
Group in an intervention study that is not exposed to what is being tested
Placebo
Inactive substance similar in appearance to the drug/vaccine being tested. Given to the control group.
Placebo Effect
Responding to the placebo as if it were the drug
Each subject is assigned to the treatment or control at ________
Random
Double-Blind
Both the doctor and the patient don’t know if the patient is getting the drug or the placebo
Cohort Study
Following large numbers of people, who decide if they belong in the “exposed” group or the control group.
Tests to see if those who are “exposed” are more likely to develop a disease than those who aren’t “exposed”
Relative Risk
The measure of the strength of association obtained by cohort me intervention studies; the ratio of the incidence rate for persons exposed to the factor to the incidence rate of for persons in the unexposed group
What does a relative risk of 1.0 mean?
No association exists between the disease and exposure
What does a relative risk of greater than 1.0 mean?
Increased risk from exposure
What does a relative risk less than 1.0 mean?
Decreased risk from exposure
Case Control Study
Epidemiologic study that starts with pkeople who are already I’ll and look back to determine their exposure
What do you compare those with the disease with in a case control study?
Controls, or healthy people who match the cases s much as possible in age, sex, and other factors relevant to the disease
What does a case control study estimate?
The strength of the association between exposure and disease with an odds ratio
How do you calculate an odds ratio?
Exposed subjects (case group) / Nonexposed subjects (case group)
divided by
Exposed subjects (control group) / Nonexposed subjects (control group)Epidemiology is the study of __________ and _________ determinants of disease frequency in human populations.
distribution ; determinants
