Separating sample into groups and analyzing the groups
What is stratification
Assess outcome and exposure at same time
Generates hypotheses
Prevalence can be calculated
Cannot demonstrate causality
What is cross-sectional study
Dichotomous outcome, comparing 2 groups
What is chi-square
Relative risk = 2.9
Exposure: Poor diet
Outcome: Diabetes
The risk of diabetes among those with poor diet is 2.9 times the risk of diabetes among those without poor diet.
# new cases of disease in a time period / total person-years
What is incidence rate
Ensuring equal distribution of confounders in experimental/intervention studies
What is randomization
Population level data is utilized
Quick and inexpensive
Can't confirm correlation because individuals are not interviewed
What is ecological study
Continuous outcome, comparing 2 groups
What is t-test
Exposure = Bee stings
Outcome = Heart attack
The odds of bee stings among those with heart attacks is 10.2 times the odds of bee stings among those without heart attacks.
Number of people with a disease in a population at one point in time/ Total in the given population at same point in time
What is prevalence
Ensuring equal distribution of confounders and must be maintained in both design of the study and analysis.
What is matching
Exposure is first assessed
Can demonstrate temporal relatioships
Rare exposures can be looked at
Can look at multiple outcomes
What is cohort study
Continuous outcome, comparing 3+ groups
What is ANOVA
Relative risk = 0.32
Exposure =Seeing a puppy
Outcome= Dying of cuteness
The risk of dying of cuteness among those who saw a puppy is 0.32 times the risk of dying of cuteness among those who did not see a puppy.
(# dying from disease / # people with disease) X 100
What is case-fatality rate
Limits study participants, but may limit generalizability of the study
What is restriction
Participants chosen based on outcome
Good for rare diseases
Relatively inexpensive
Subject to recall bias
What is case-control study
Continuous outcome, comparing many groups
What is linear regression
Odds ratio =1.00
Exposure = Pollen
Outcome= Getting a haircut
There is no association between being exposed to pollen and getting a haircut.
(# dying from disease / # deaths in population) X 100
What is proportionate mortality rate
Controls for multiple confounders at once and involves construction of a mathematical model
What is multivariable analysis
Exposure is assigned/controlled by researchers
Most powerful way to measure cause and effect relationships
Individually-based
What is a clinical trial
Dichotomous outcome, comparing many groups
What is logistic regression
Risk ratio = 0.56
Exposure = Rock climbing
Outcome = Head injury
The risk of head injury among those who rock climb is 0.56 times the risk of head injury among those who do not rock climb.
(Incidence in placebo group - Incidence in treatment group) / Incidence in placebo group
What is efficacy