Lecture 14 Flashcards
what is cumulative incidence
estimate of the risk that an individual will experience an event or develop a disease during a specified period of time
define odds
the ration of the probability to develop illness (to die or have certain outcome) and stay healthy.
what values can the odds be
from 0 to infinity
what is the chance of getting sick, if odds are <1
the chances of getting sick are small, as the probability of getting sick is less rather staying healthy (the probability of staying healthy is larger than developing an illness)
when odds =1, what is the likelihood of developing an illness?
it’s equally likely to develop illness and stay healthy (the probability of developing an illness is higher than staying healthy)
what does teh risk ratio measures?
the increased risk for developing a disease when having been exposed to a risk factor compared with not having been exposed to the risk factor. It is given by RR = risk for the exposed/risk for the unexposed, and it is often referred to as the relative risk.
what is the odds ratio (OR)?
is the ratio of the odds of the disease in the group exposed to the factor, to the odds of the disease in the unexposed group.
odds ratio of risk factor is equal to
odds exposed to risk factor divided by odds unexposed to risk factor
odds equals to
baseline times exposure
odds exposed to risk factor equals to
odds unexposed to risk factor times odds ratio of risk factor
what method does logistic regression provides?
method for modelling a binary response variable, which takes values 1 and 0
what are we modelling with linear regression?
the probability of the event
how logistic regression model is estimated?
by using maximum likelihood method
what the logistic regression coefficients give?
the change in the log odds of the outcome for a one unit increase in the predictor variable
if p-value is <0.05 then the result is
significant
