Relative Risk

EER

# of experimental group with event/total # in experimental group

RRR

(1-RR) RR is the risk in the exposed population divided by the risk in the unexposed population

number needed to treat

NNT=1/ARR usually expressed over a particular time frame

risk of getting disease in exposed population

a/(a+b)

risk of getting the disease in the exposed population over the risk in the unexposed population

a/(a+b)/c/(C+d) aka relative risk

risk of getting disease in unexposed population

c/(c+d)

experimental/exposed event rate

is the risk of getting the positive (or negative) event in the experimental (or exposed) population

when relative risk is under 1

it means it is protective. exposed group less likely to develop disease than other group

absolute risk reduction (ARR)

risk in the unexposed population minus the risk in the exposed population control event rate-experimental event rate

control event rate (CER)

risk of getting the positive (or negative) even in the control group ( or non exposed group) this is also expressed as a percentage

relative risk

we can measure the incidence of an outcome in the exposed group vs in the unexposed group ratio of disease in exposed groups versus incidence of disease in the unexposed