Class 8-10: Asso.

Question 1

2x2 table is searching for

Answer 1

Associations

Question 2

Counterfactual theory

Answer 2

The attempt to create all people in the group as equal “IF” the exposure/Tx/disease had NOT occurred…This is impossible to create. Once a smoker has smoked…he has smoked and that can be reversed.

Question 3

Our best attempt at Counterfactual theory

Answer 3

Exchangability

Question 4

Exchangeability

Answer 4

Comparability

Question 5

Label for columns of the 2x2

Answer 5

Disease/outcome

Question 6

Label for the rows of the 2x2

Answer 6

Yes/No: if exposure/Tx occurred

Question 7

Absolute Difference

Answer 7

Subtracting frequencies

Question 8

Relative differences

Answer 8

Division of frequencies

And division of proportions

Question 9

Which is larger relative or absolute differences

Answer 9

Relative differences are larger

Question 10

Risk is a frequency/ratio/proportion?

Answer 10

Proportion

Question 11

Probability of outcome

Answer 11

A simple percentage

Question 12

Absolute Risk reduction (ARR)

Answer 12

This is the absolute difference of the outcome attributable to exposure difference between groups.

Question 13

Relative risk reduction (RRR)

Answer 13

ARR / Risk of unexposed

Question 14

Number needed to Treat (NNT) / Number needed to harm

Answer 14

Attempt to recreate relative risk into whole people… 1 / Absolute risk reduction—This is the number of patients needed to be treated to receive the stated benefit/harm

Question 15

Risk ratio

Answer 15

Ratio of the 2 risks:

[ Risk of outcome (exposed) / risk of outcome (unexposed)]

Question 16

All ratios:

Answer 16

Compare 2 groups and describe likelihood of event/outcome in 1 group compared to the other

Question 17

If the ratios have the ratio of 1.0, then the outcome is:

Answer 17

Equally as likely

Question 18

If risk ratio is > 1 then the outcome is:

Answer 18

MORE likely to occur than the comparison group

Question 19

If the risk ratio is

Answer 19

Less likely to occur in the comparison group

Question 20

If the risk ratio is between 1-1.99 how do we compare to comparison group

Answer 20

Use the decimal value as a %

Question 21

If the risk ratio is >2 how do we compare to comparison group

Answer 21

‘X’ times greater than: 6.18=6.18 times greater

Question 22

If the risk ratio is between .00001 - .99 how do we compare to comparison group

Answer 22

Subtract from 1…then convert to %;

0.73 = 27% decreased

Question 23

When interpreting ratios, there are 3 factors to consider:

Answer 23

1. Group (intervention/placebo)
2. Direction (increase/decrease)
3. Magnitude (%/X)

Question 24

Odds:

Answer 24

Frequency of an outcome occurring vs. not occurring

Question 25

Odds Ratio:

Answer 25

[ odds of exposure (diseased) / odds of exposure (non-diseased)]——can also cross multiply