Correlation, regression, relative risk and survival analysis

Question 1

if we get spss to calculate the correlation coefficient, what is the r value?

Answer 1

this is the r value / correlation coefficient

Question 2

what numbers can the r value be between?

Answer 2

-1 to 1

Question 3

is the r value was 0, what does this indicate about the correlation line?

Answer 3

that the line is flat or that the scattergram is everywhere

Question 4

if the r value is 0, what does this say about the 2 variables and how they are correlated?

Answer 4

that the 2 variables are not correlated

Question 5

if the r value is positive, what does this say about the 2 variables and how they are correlated?

Answer 5

+ correlation

Question 6

what is the p value in a correlation based upon?

Answer 6

the null and alternative hypothesis

Question 7

in this case, the p value is 0.001 therefore which null do we reject/accept?

Answer 7

it is smaller than 0.05 therefore there is a correlation

Question 8

besides using correlation coefficient, what other model can we use to express relation?

Answer 8

regression model

Question 9

explain correlation coefficient, how we know whether the c coefficient is strong or weak etc

Answer 9

Question 10

write the r value for these scatter plots

Answer 10

r= -1

Question 11

write the r value for these scatter plots

Answer 11

r = -0.6

Question 12

write the r value for these scatter plots

Answer 12

r = 0

Question 13

write the r value for these scatter plots

Answer 13

r = +1

Question 14

write the r value for these scatter plots

Answer 14

r = +0.3

Question 15

write the r value for these scatter plots

Answer 15

r = 0

Question 16

How is regression different to correlation

Answer 16

Question 17

which equation does linear go by?

Answer 17

Y= B + mX

Question 18

In linear regression, what does B represent?

Y= B + mX

Answer 18

Intercept of x on the y axis

Question 19

In linear regression, what does m represent?

Y= B + mX

Answer 19

the slope of this line

Question 20

what does the slope of 0.7 mean?

Answer 20

It means that

Question 21

Answer 21

4 - the mean

Question 22

Answer 22

no - as we have more info on their sugar consumption - we can then use correlation / linear regression.

Question 23

what is meant by risk?

Answer 23

the number of ppl that have PD out of the total number of ppl in each group are those that have the risk

Question 24

Answer 24

36.4% - vitamin
62.9% placebo

so diff is 36.4-62.9 = -26.5%

Question 25

Answer 25

Question 26

if we assume the null hypothesis, that there is no risk between the 2 groups, so ratio is the same, what risk ratio would we expect? so 1 is the reference value that we compare the risk ratio with

Answer 26

1 so in our example, we compare 0.58 to 1

Question 27

why is odds ratio calcualted?

Answer 27

Question 28

define odds ratio

Answer 28

Question 29

when we have an odds ratio of 1, what is the associated?

Answer 29

no association between the disease and the exposure

Question 30

when we have an odds ratio of >1 or <1, what is the associated?

Answer 30

there is an association between exposure and disease

Question 31

Answer 31

Question 32

when reporting the relative risk, what number do we have to report?

Answer 32

whichever you choose, they're all correct

Question 33

the odds ratio with always be bigger/smaller than the corresponding risk ratio if RR>1?

Answer 33

bigger (the harmful or protective effect always appears larger)

Question 34

the odds ratio with always be bigger/smaller than the corresponding risk ratio if RR<1?

Answer 34

smaller (the harmful or protective effect always appears larger)

Question 35

interpretation of the odds ratio: the magnitude of the inflation depends what?

Answer 35

on the prevalence of disease

Question 36

what would the calculation be?

Answer 36

Question 37

so we can use risk ratio or odds ratio, whats better?

Answer 37

either is fine, just a diff way of doing it

Question 38

what 2 things does survival analysis take into account?

Answer 38

- how long it takes (time to event) - taking into account whether the event happened or didn't happen

Question 39

define what is statistical analysis?

Answer 39

Question 40

what is an event by definition?

Answer 40

Question 41

what types of data (like what types of studies) does survival analysis accomodate?

Answer 41

Question 42

survival analysis: terms define time-to-event

Answer 42

Question 43

survival analysis: terms define censoring

Answer 43

Question 44

One of the simplest forms to perform a survival analysis is called the Kaplan-Meier curve. What is it commonly used to describe?

Answer 44

the survivorship of study populations

Question 45

One of the simplest forms to perform a survival analysis is called the Kaplan-Meier curve. it is commonly used to describe the survivorship of study populations how many groups is it commonly used to compare?

Answer 45

2

Question 46

One of the simplest forms to perform a survival analysis is called the Kaplan-Meier curve. it is commonly used to describe the survivorship of study populations what presentation form is it found in?

Answer 46

intuitive graphical presentation (a graph)

Question 47

this table will be given in the exam