Risk

Question 1

what is risk?

Answer 1

the chance that something will happen to you if it hasn’t already

Question 2

formula for risk

Answer 2

number of incidents/ number of potential incidents

Question 3

what are the two ways to compare risk

Answer 3

• Relative risk - ratio of two risks (30%/10% = 3%)
• Attributable risk - difference between two risk (30 - 10 = 20%)

Question 4

what are better ways to prevent risk

Answer 4

natural frequencies
number needed to treat (NNTT)

Question 5

how can risk be misleading

Answer 5

if bowel cancer chances increases by 20% it says how much the risk has increased but not how much risk was there to begin with. atributable risk could be only 1%

Question 6

natural frequencies

Answer 6

uses imaginary groups of people. a natural frequencies approach would say:
If 100 people, who previously didn’t eat bacon
sandwiches, started doing so, then 1 extra
person would get bowel cancer.

Question 7

number needed to treat

Answer 7

this says how many people would have to change their diet/lifestyle to get one additional improvement.

for bacon, the number needed to treat is 100 because 100 people would have to start eating bacon for 1 extra bowel cancer case to occur.

The NNTT is one over the attributable risk

Question 8

confounding

Answer 8

occurs when the real risk is:
- not recorded in the study
- associated with something that is recorded

Question 9

Why is their risk calculation incorrect? What information would they need to make a proper risk calculation?

Answer 9

The 66% means (number of weekend accidents)/(total accidents).

However the risk is calculated from
(number of weekend accidents)/(number of people skateboarding on weekend)

The reason there are more accidents on weekends could simply be more people are skateboarding on weekends. They need to know how many people are skateboarding before working out the risk