Statistics Flashcards
How to calculate relative risk (RR)?
Risk in treated group (probs) / risk in control (probs)
What does RR<1 mean?
Risk of outcome LESS in treatment group
What dose RR=1 mean?
Risk equal in both groups
What dose RR>1 mean?
Risk of outcome GREATER in treatment group
Why absolute risk might be better than RR for interpretation?
Less susceptible to misinterpretation
When is using RR good?
Good when event is rare?
How to calculate absolute risk (risk difference)?
Risk in treatment group (probs) - Risk in control group (probs)
What does RD < 0 mean?
Risk of outcome LESS in treatment group
What does RD=0 mean?
Risk of outcome equal in both groups
What does RD > 0 mean?
Risk of outcome GREATER in treatment group
What is the definition of the NNT?
The number needed to treat with the new treatment in order to prevent one adverse event occurring
How to calculate NNT?
1/ absolute risk reduction (absolute risk difference)
What is the definition of the odds ratio?
The ratio of the odds in the intervention group to the odds in the control group
What is the definition of the odds?
The ratio of the number having an even to the number without the even
How to calculate odds?
No. with event/ no. without event
