Definitions

Question 1

Prevelance

Answer 1

The amount of people in a set population who currently have that disease

(Doesn’t have a time frame)

Question 2

General Fertility Rate

Answer 2

No of live births per 1000 fertile women aged 15-44

Question 3

Crude Birth Rate

Answer 3

Number of live births per 1000 of the population

Question 4

Total Period Fertility Rate

Answer 4

Average number of children born to a hypothetical woman in her lifetime

Question 5

Age Specific Death Rate

Answer 5

Deaths per 1000 people in a particular age group

Question 6

Confounding Factor

Answer 6

A confounder is associated with both the exposure and outcome of interest but does not lie on the causal pathway between exposure and outcome

Question 7

What does an SMR do?

Answer 7

Compares a cohort to a reference population/general public

Question 8

Why is an incidence rate a measure of absolute risk?

Answer 8

Because it is a rate/it is within a certain time frame

Question 9

Define Census

Answer 9

Simultaneous recording of data of all people in a defined area at a particular time

Question 10

How do you calculate an Incidence Rate Ratio? (IRR)

Answer 10

Rate unexposed

Question 11

What would an SMR reading of greater than 100 suggest? (SMR>100)

Answer 11

This would suggest there is excess mortality in the cohort

Question 12

What would an SMR of less than 100 suggest? (SMR

Answer 12

That there is less mortality in the cohort than in the general population

Question 13

What would a positive IRR suggest?

Answer 13

That there is more death or incidence in the exposed group compared to the unexposed group.
The increased rate of disease is due to an increased rate of exposure

Question 14

Interpret an IRR of 2.25

Answer 14

The exposed group are 2.25 times as likely to get…. Compared to those who were unexposed.

Question 15

What would the NH be when you’re calculating risk difference?

Answer 15

0

Because same number-same number=0

Question 16

If a P value is greater than 0.05…

• are the findings statistically significant?
• can you reject the null hypothesis?

Answer 16

The results are NOT statistically significant

You canNOT reject the NH

Question 17

If the NH lies within the given confidence intervals, what will the P value be?
How would you interpret this?

Answer 17

P>0.05
Can’t reject NH as it could be a true value.
Not statistically significant

Question 18

Incidence Rate

Answer 18

The number of new cases of a certain disease per 1000 of the population in a given amount of time

(Per thousand person years)

Question 19

How would you adjust for confounders? (One way)

Answer 19

Use matched case-control

Where you match a case with a control who has the exact same date of birth and is same age etc etc

Question 20

What effect on an odds ratio does selection bias have?

Answer 20

Underestimates odds ratio

Question 21

What effect does information bias have on an odds ratio?

Answer 21

Shrinkage to null

Question 22

What measure would you use for an internal cohort study?

Answer 22

IRR

Question 23

What measure would you use for an external cohort study?

Answer 23

SMR

Question 24

Why can case controls only give a relative risk?

Answer 24

Because they provide us with a ratio, not a rate

Question 25

If more of the control people underestimated their exposure in a case control study, what would the effect on the association be?

Answer 25

Overestimate the association as it would make D value larger (numerator)

Question 26

If more case people underestimated their exposure, what effect would it have on the interpretation of the association?

Answer 26

Underestimate association

Question 27

What do you call it when both cases and controls randomly misclassify?

Answer 27

Shrinkage to null

Question 28

Why is SMR good?

Answer 28

Accounts for confounders/takes them into account