Population health

Question 1

What is the aim of intention to treat analysis in a clinical trial?

Answer 1

Reduce selection bias

Question 2

How is rate of a disease development calculated?

Answer 2

(new cases) / (total person time of follow up)

Question 3

How is relative risk calculated?

What does it tell you?

Answer 3

(Risk exposed) / (Risk unexposed)

Re/Ru

indicates the relative magnitude of change in risk/rate of outcome, associated with exposure

Question 4

What is the aim of blinding in a clinical trial?

Answer 4

Reduce information/observor bias

Question 5

How is attributable risk percentage calculated?

What does it tell you?

Answer 5

AR% = (Re - Ru)/Re x 100

Proportion of incident disease among exposed people that is due to exposure

Question 6

What is the aim of randomisation in a clinical trial?

Answer 6

Reduce influence of confounding variables

Question 7

How is risk calculated?

Answer 7

(Number of new cases in a defined period) / (population at risk)

Question 8

How is attributable risk calculated?

What does it tell you?

Answer 8

(Risk exposed) - (risk unexposed)

Ru-Re

indicates the absolute magnitude of change in risk/rate of outcome, associated with exposure

Question 9

What is the downside of intention to treat analysis in a clinical trial?

Answer 9

Underestimates treatment effect

Question 10

How is population atributable risk percentage calculated?

What does it tell you?

Answer 10

100 x (Rt-Ru)/Rt

Proportion of incident disease among whole population that is due to exposure.

Question 11

How is population attributable risk calculated?

Answer 11

(Rate in whole population) - (Ru)

Question 12

What are the 3 essentail features of a clinical trial?

Answer 12

Randomisation

Blinding (aka masking)

Intention-to-treat analysis

Question 13

What are the 9 Bradford Hill Criteria for causality?

Answer 13

temporal relationship

strength
dose-response relationship
consistency
plausibility
exclude alternatives
experimental evidence
specificity
coherence

Question 14

How is NNT calculated?

Answer 14

1 / (absolute rate/risk reduction)

Question 15

How is sensitivity calculated?

Answer 15

_ True positive _

True pos + False Neg

Question 16

How is positive predictive value calculated?

Answer 16

_ True positive _

True pos + False Pos

Question 17

How is specificity calculated?

Answer 17

_ True negative _

True neg + False pos

Question 18

How is negative predictive value calculated?

Answer 18

_ True negative _

True neg + False Neg

Question 19

What are the axes of a receiver operating characteristic curve?

Answer 19

y = sensitivity

x = 1 - specificity

Question 20

What is the main purpose of a meta-analysis?

Answer 20

To increase power

Question 21

What should you consider when wondering if a study is relevant to your patient?

Answer 21

PICOT

Population

Intervention

Comparator

Outcome

Time

Question 22

What are the 4 elements of autonomy in medical ethics?

Answer 22

Freedom to make your own decisions. No coercion No manipulation No deceit

Question 23

What percentage of travellers visiting a developing country will develop a health problem?

Answer 23

50%

Question 24

What is the most common cuase of death in travellers?

Answer 24

Cardiovascular disease

Question 25

Define beneficence in a medical ethics context

Answer 25

Promote health and well-being

Question 26

What are the 5 ethical principles?

Answer 26

Non-maleficence Beneficence Autonomy Justice Dignity (never be a jerk doctor)

Question 27

What is the most common serious medical condition in travellers?

Answer 27

Malaria

Question 28

Define non-maleficence is a medical ethics contect

Answer 28

Do no harm, or minimise harm

Question 29

Which ethical principle is informed consent most important for?

Answer 29

Autonomy

Question 30

Define respect for dignity in a medical ethics context

Answer 30

All people are of equal moral worth

Question 31

What is the most effective public health measure to decrease tobacco usage?

Answer 31

Increasing taxation

Question 32

How is population atributable risk percentage calculated?

What does it tell you?

Answer 32

100 x (Rt-Ru)/Rt

Proportion of incident disease among whole population that is due to exposure.