association and survival analysis

Question 1

positive association

Answer 1

higher value for on factor leads to higher value for the other factor (risk factor)

Question 2

negative association

Answer 2

higher value for one factor leads to lower value for other factor (protective factor)

Question 3

if 60/100 smokers get lung cancer, what is risk?

Answer 3

60/100 = 60%

Question 4

if 60/100 smokers get lung cancer, what are the odds?

Answer 4

60/40 = 1.5

Question 5

CIR = 1
CIR > 1
CIR

Answer 5

=1 = risk is same in exposed and unexposed 
>1 = risk is greater in exposed (risk factor)

Question 6

IDR = 1
IDR > 1
IDR

Answer 6

=1 = rate is same in exposed and unexposed 
>1 = rate is greater in exposed (risk factor)

Question 7

OR = 1
OR > 1
OR

Answer 7

=1 = odds are same in exposed and unexposed 
>1 = odds are greater in exposed (risk factor)

Question 8

equation to estimate RR from OR

Answer 8

RR = OR/ 1-Rc + (Rc x OR)

Question 9

attributable risk

Answer 9

rate of disease in exposed that can be attributed to the exposure

Question 10

attributable risk proportion

Answer 10

proportion by which the incidence rate in the exposed would be reduced if the exposure was eliminated

Question 11

population attributable risk

Answer 11

rate of disease attributed to an exposure in a population

Question 12

population attributable risk proportion

Answer 12

proportion by which the incidence rate in a population would be reduced if the exposure was eliminated

Question 13

current/period life table

Answer 13

summarizes mortality of the population over a brief period

Question 14

cohort/generational life table

Answer 14

described the actual survival of a group of people born around the same time

Question 15

clinical life table

Answer 15

describes outcomes in a cohort according to their treatment/exposure history

Question 16

internal validity

Answer 16

degree to which the index and comparison groups are well selected/compared such that any difference between them can be attributed to the hypothesized effect under investigation

Question 17

external validity

Answer 17

able to produce unbiased inferences regarding a target population

Question 18

another term for external validity

Answer 18

generalizability

Question 19

chance

Answer 19

an event that occurs at random and affects the outcome

Question 20

how is chance accounted for in statistics?

Answer 20

P-value

Question 21

define confidence interval 95%

Answer 21

95/100 times, the true value will fall into the range

Question 22

if CI contains___, fail to reject null hypothesis

Answer 22

null value

Question 23

null value for RR, OR, any ratio

Answer 23

1

Question 24

null value for AR, PAR

Answer 24

0

Question 25

what is selection bias?

Answer 25

bias due to systemic differences between those who take part in the study and those who do not

Question 26

what is response bias?

Answer 26

bias due to systemic difference between those who choose to take part in the study and those who do not

Question 27

what is another term for response bias?

Answer 27

self-selection bias

Question 28

what is information bias?

Answer 28

flaw in measuring exposure/outcome data that results in differing accuracy of information between groups

Question 29

examples of information bias (8)

Answer 29

interviewer, recall, reporting, instrumental error, measurement, digit preference, selective loss to f/u, misclassification

Question 30

non-differential misclassification

Answer 30

same misclassification happens in all groups, tendency toward null value

Question 31

differential misclassification

Answer 31

varied missclassifications in groups, more problematic

Question 32

3 qualifications for a confoudning variable

Answer 32

1) risk factor for the outcome 2) associated with the exposure 3) not an intermediate in the causal pathway

Question 33

interaction

Answer 33

interdependent operation of 2+ causes to produce or prevent outcome

Question 34

effect modifier

Answer 34

factor that modifies the effect of a causal factor under study

Question 35

how to control for 3rd variables in experimental designs?

Answer 35

randomization

Question 36

restriction

Answer 36

limiting participation to individuals in a specific category of the confounder

Question 37

matching

Answer 37

make study groups and comparison groups similar with respect to confounders

Question 38

stratification

Answer 38

separate sample into many sub-sample classes

Question 39

pooling

Answer 39

rarely used

Question 40

multiple linear regression used for___

Answer 40

continuous dependent outcomes

Question 41

multiple logistic regression used for ___

Answer 41

dichotomous outcomes

Question 42

cox/poisson used for___

Answer 42

rate from cohort or experimental study are compared