hsci 230 here Flashcards
What is Relative Risk?
Evaluates strength of association
What is Attributable risk?
The burden of disease attributable to exposure among those exposed
What is Population attributable risk?
The burden of disease attributable to exposure in the population.
What is Attributable Fraction?
Identifies exposures that cause most disease among those exposed
What is population attributable fraction?
Identifies the specific exposures that cause most disease in a population
What are the 3 main alternative explanations we have to consider in epidemiological data?
- chance
- bias or error
- confounding
What is random sampling error
each sample will include slightly different people and characteristics will vary from those in others, by chance
what is the best way to reduce random sampling error
increase the size of the study sample as far as is practical
what are the 4 possible outcomes to any study
2x2 table no association, association (truth unknown and study results known)
how to tell a p value
if p value is less than 0.05, the probability that the result would have arisen by chance is less than 5 %
what does the confidence interval mean (95%)
if we were to repeat the study many times with different samples of people, then 95% of the 95% confidence intervals we calculated would include the true value
what does a wide confidence interval mean
less precision
what does a narrow confidence interval mean
good precision
what are the two pieces of knowledge needed for power or sample size calculations
- the smallest difference that we want to be able to detect
- the prevalence of the exposure and/or incidence of the outcome in the population
- how precisely we want to measure the effect
what is an effect in epidemiology
describes the way health is changed by the agent
