Chapter 2 (Exam 2 Review) Flashcards
risk factor
any attribute or characteristic of an individual that increases or decreases the likelihood of developing the outcome of interest
exposure
the condition of being subjected to a risk factor that may have a significant impact on health
outcome
the possible results that may stem from exposure to risk factors; typically refers to the presence or development of disease or health conditions
Incidence
the number of new cases of a disease in a population during a specific period
* formula : # of new cases/population at risk during period * 10^n
prevalence
the total number of existing cases (new and old) of a disease in a population at a specific time
formula: # of old case and # of new cases/ population at risk during period * 10 ^n
odds ratios
compares odds of an event occurring in one group to the odds of it occurring in another group.
- favorable vs. unfavorable
- 1: 1
- current or existing cases (NOT NEW)
- (a/b) / (c/d)
risk ratios
compares the probability (risk) of an event occurring in one group to the probability of it occurring in another group
- considers all outcomes
- incident cases
- favorable/total possible
- [ a/(a+b) ] / [ c/(c+d) ]
Number Needed to Treat
confounding
an outside variable that influences both the risk factor & the health outcome, leading to false association
- “adjust or control”
- single factor
effect modification
occurs when the effect of the primary exposure on an outcome of interest differs defending on the level of another variable
- diff association
- btwn groups ex: gender
cross sectional study
risk factors/ exposure to risk factors and the presence or absence of the outcome of interest are measured at the same time
- no temporal sequence
- easy & quick to conduct
- can’t infer causation
- not appropriate for hypothesis testing
(OR)
case control study
the frequency and odds of past exposure to potential risk factors for the outcome are compared between groups
> participants are selected based on presence or absence of an outcome of interest
- relatively quick
- can assess mutliple risk factors
- subject to recall bias
- temporal sequence is iffy
(OR)
prospective cohort study
type of observational study focused on following a group of people over a period of time , collecting data on their exposure to a risk factor of interest
- outcomes are tracked over time to investigate the association between exposure and outcome
- temporal sequence
- loss of participants to follow-up
- expensive and time-consuming
(OR & RR)
Randomized Control Trial
considered the “gold standard” research design
- participants are recruited and randomly allocated to an “experimental” or “control” condition
- limited generalizability
- dropouts and lack of compliance
(OR & RR)
temporal sequence
risk factor exposure must come before the outcome of interest
Strength of Association
clinically meaningful difference in risk is present between exposed and unexposed
- OR/RR of 1.0 = no association
- the farther away from 1.0 an OR/RR is in either direction, the stronger the association (p < 0.05)
Consistency
the association is always present between exposure and outcome
- analyses must be robust (e.g., adjusted for confounding ) and occur across different populations, study designs, or different measures of physical activity
Dose Response
the association between exposure and outcome becomes stronger with increased exposure
Biological Plausibility
we can explain the association through established biological/ physiological mechanisms
