Epidemiology Exam Flashcards
Two groups given different medications to see which medication performs the best…
Clinical Trial
Looking at people who have have been EXPOSED compared to those who have not been EXPOSED over the course of a few years to see if an outcome occurs and if it it’s linked to exposure or not…
Prospective Cohort
Looking BACK at people who have have been EXPOSED compared to those who have not been EXPOSED to see if an outcome occurred and if it was linked to exposure or not…
Retrospective Cohort
You want to know if two things are associated…so you call a bunch of people and ask about their habits to help you find out…
Cross Sectional
To calculate PREVALENCE…
The people WHO DO HAVE divided by the TOTAL NUMBER OF PEOPLE WHO COULD HAVE.
To calculate SENSITIVITY…
True positives / True positives + False negatives.
To calculate SPECIFICITY…
True negatives / True negatives + False positives
To calculate POSITIVE PREDICTIVE VALUE…
True positives / True positives + False positives
To calculate NEGATIVE PREDICTIVE VALUE…
True negatives / True negatives + False negatives
Why do we randomize?
Decrease the likelihood that observations are due to chance
If you give some people an actual drug and some people a fake drug but people in both groups improve…this is likely due to ____
Placebo effect
You are doing a study which requires you to follow up with patients, but some of them are morons and drop out…but you still include the results associated with the dropouts in your study. This is an example of____
Intention to treat
If it is a new drug…chances are a ____ was utilized to get it approved.
Randomized controlled clinical study
If you are trying to see if “one thing” affects another…the “one thing” is the ____
Independent variable
To calculate RISK of something for EXPOSED people…
Those exposed WITH the outcome / Total number of people exposed
To calculate RISK of something for UNEXPOSED people…
Those unexposed WITH the outcome / Total number of people unexposed
To calculate RISK RATIO…
Risk of EXPOSED / Risk of UNEXPOSED
Making sure you account for all possible factors that may be associated with outcome into your study prevents ____ from contaminating data
Confounding Factors
% of people with a characteristic/disease in a population at a certain point in time is ____
Prevalence
If two people perform two different tests to determine if a disease is present…the one performing tests with HIGHER SENSITIVITY (regardless of specificity) will likely correctly identify ____ people with the disease
MORE. You will have a higher chance of catching MORE people with the disease (letting fewer go).
You have a hypothesis you are trying to test. You perform the test and your p-value ends up being a very low number (0.001) which forces you to ____ “null hypothesis”.
REJECT. Your hypothesis was CORRECT and you could safely REJECT the null.
If an odds ratio associated with an exposure is < 1.0…then the exposure is…
PROTECTIVE (subjective). Whatever the exposure is…it is associated with LOWER ODDS of outcome.
If an odds ratio associated with an exposure is > 1.0…then the exposure is…
HARMFUL (subjective). Whatever the exposure is…it is associated with HIGHER ODDS of outcome.
If an odds ratio associated with an exposure is = 1.0…then the exposure…
DOES NOT AFFECT THE ODDS OF OUTCOME
If a 95% confidence interval range is given and DOES NOT include 1.0 (null value), then it is ____
Statistically significant
If results are found to be statistically significant at the 5% level…this means that if an association was made between two things…there is a ____% possibility that the association occurred by chance alone.
5%
If the results of a study can be applied to other populations…this study would have good ____
External validity
Survey studies sort of suck because they are limited in many ways…including…
The fact that a person volunteers may mean they are biased in the first place, survey answers may not be accurate, in order to be considered externally valid there must be standardizing of the survey, and other stuff can suck too…just answer all of the above