Definitions

Question 1

Define attributable risk

Answer 1

Measure of exposure effect that indicates how much greater frequency of disease is in the exposed group vs unexposed. Risk attributable to exposure of interest.

Question 2

How is attributable risk calculated

Answer 2

Incidence in the exposed-incidence in the unexposed

Question 3

Define incidence

Answer 3

No. of cases of the outcome of interest occurring in a defines population of a defined period of time. Probability or risk

Question 4

How do you calculate odds ratio

Answer 4

odds of exposure in diseased group/ odds of exposure in the disease free group

Question 5

Define odds ratio

Answer 5

Ratio between two odds that is reported in case-control studies instead of relative risk

Question 6

How is odds ratio interpreted

Answer 6

1 = no association
>1 exposure more likely in case group
<1 exposure less likely in case group

Question 7

Define prevalence

Answer 7

No. of cases of an outcome of interest in a defined population at a particular point in time

Question 8

How is point prevalence calculated

Answer 8

No. of cases in a defined population at one point/ no. of persons in a defined population at one point

Question 9

Define P value

Answer 9

The probability of obtaining the study result if the null hypothesis is true

Question 10

What is the difference between prevalence and incidence

Answer 10

prevalence is all the cases at present while incidence is NEW cases

Question 11

Describe relative risk

Answer 11

Measure of association between an exposure and disease as a ratio of incidence rate in the exposed group and the incidence rate in the non-exposed group

Question 12

How is relative risk calculated

Answer 12

Incidence in the exposed group/incidence in the unexposed group

Question 13

How is relative risk interpreted

Answer 13

1 = incidence in the exposed and unexposed are identical
>1 = positive association

Question 14

Define sample

Answer 14

A relatively small number of observations from which a population is described

Question 15

Define variation

Answer 15

Variation of observations in a single sample

Question 16

What do you take into account when evaluating statistical association

Answer 16

Chance
Bias
Confounding
Causal effect

Question 17

Define routine data

Answer 17

data that are routinely collected and recorded in an ongoing systematic way, often for administrative or statutory purposes without a specific research question

Question 18

Give examples of routine data

Answer 18

deaths, hospital admissions, screening, immunisation uptakes, census counts, GP consultation data

Question 19

Give 3 major sources for routine data

Answer 19

Census
Health survey for England
NHS inpatient survey on patient experience

Question 20

What are the advantages for routine data

Answer 20

Cheap
Collected and available
Standardised collection procedures 
Relatively comprehensive
Wide range of recorded items
Available for past years
Need careful interpretation

Question 21

What are the disadvantages for routine data

Answer 21

May not answer the question
Incomplete ascertainment
Variable quality 
Validity may be variable
disease labelling may vary

Question 22

Define age standardised death rates

Answer 22

How many people die each year and why

Question 23

Define standardised mortality ratio

Answer 23

ratio between the observed number of deaths in a study population and the number of deaths would be expected

Question 24

How do you calculate age standardised death rates

Answer 24

no. of observes death/ no. of the expected death if experienced the same age specific rates as standard population

Question 25

Why is age standardised death rates useful

Answer 25

helps health authorities determine whether they are focusing on the right kinds of public health actions that will reduce the no. of preventable deaths and disease