Powerpoint

Question 1

What is a census?

Answer 1

Simultaneous recording of demographic data to all persons in a defined area

Question 2

Why is a census useful?

Answer 2

Allocate resources
Project population
Trends

Question 3

What is crude birth rate?

Answer 3

Number of live births per 1000 people

Question 4

What is general fertility rate?

Answer 4

Number of live births per 1000 fertile women between 15-44

Question 5

What is total period fertility rate?

Answer 5

Average number of children born to a hypothetical women in her life

Question 6

What is incidence?

Answer 6

Number of new cases of disease per 1000 per year

Question 7

What is prevalence?

Answer 7

Amount of people who currently have the disease in a set population

Question 8

What is Incidence rate ratio?

Answer 8

Incidence rate of two separate populations with varying exposure to see if exposure causes a certain disease

Question 9

What is a confounding factor?

Answer 9

Something that effects outcome and exposure e.g. Bournemouth has more cancer, age is a confounding factor because with age get more cancer and more likely to move to bournemouth

Question 10

What rate takes confounding factors into account?

Answer 10

Standardised mortality rate

Question 11

What is variation?

Answer 11

Difference between observed and actual values- error factor to allow for variation

Question 12

What are confidence intervals?

Answer 12

Range of values that we can say with confidence that the actual value will lie in between this range in 95% of cases

Question 13

What is the p value?

Answer 13

5%

Probability of obtaining a test statistic

Question 14

What is biasing?

Answer 14

The deviation of the result from the truth via certain processes

Question 15

What is selection bias?

Answer 15

Error due to systematic differences in the ways in which the two groups were collected e.g. allocation bias and healthy worker effect

Question 16

What is information bias?

Answer 16

Error due to systematic misclassification of subjects in the group e.g. recall bias and publication bias

Question 17

What is a cohort study?

Answer 17

Recruiting disease free individuals and classifying them according to their exposure status
They are then followed up for extended periods and disease progress in monitored and incidence rate is calculated

Question 18

What is a cohort study good for?

Answer 18

Rare exposures or long time for diseases to develop

Question 19

What is prospective?

Answer 19

When disease free individuals are recruited and followed up

Question 20

What is retrospective?

Answer 20

Disease free individuals are recruited, exposure rates are calculated from previous documentation and followed up

Question 21

Give an example of a cohort study

Answer 21

1000 children followed up from 0-5
300 parents smoked and 75 developed asthma
700 parents didn’t smoke and 105 developed asthma
=1.667x more likely to have asthma if smoked

Question 22

What is an internal comparison?

Answer 22

Have sub cohorts in the group and compare exposed to unexposed- Use IRR

Question 23

What is external comparison?

Answer 23

Exposed population compared against a reference population- use SMR

Question 24

What is healthy workers effect?

Answer 24

Biasing of the result when a study involves workers compared to a reference population and is a form of selection bias as working people are more likely to be healthy so must be compared to others who work

Question 25

What is a case control study?

Answer 25

Recruits disease free individuals as controls and diseased individuals and then exposure status is then determined

Question 26

What is a case control study used for?

Answer 26

Rare diseases

Question 27

How many more controls are there than diseased?

Answer 27

x5

Question 28

How are case control studies biased?

Answer 28

Selection bias from participants from same area so same risk factors not representing the whole population
Exposure status is determined incorrectly due to looking back at history to determine exposure
Confounders removed by matching up cases with similar details

Question 29

Which type of study is cheap and quick?

Answer 29

Case-control study

Question 30

What are randomised controlled trials?

Answer 30

Experimental studies
Identify source of eligible patients and invite
allocate participants to either treatment randomly
Follow up patients identically
Minimise losses to follow up and maximise compliance with treatment
analyse data and obtain results

Question 31

What is good about randomised controlled trials?

Answer 31

Randomised so remove any confounders
Patients and doctors do not know who has the drug
Placebos are used to remove placebo effect
non-compliers would still be counted in the trial otherwise loss of randomisation
Measured by intention to treat

Question 32

What is bradford hill criteria?

Answer 32

To determine whether casual effect relationship had been established
More present, more likely to be a casual effect relationship

Question 33

How can losses be minimised in a RCT?

Answer 33

Follow up appointments at practical times
No coercion or inducements
honest patients

Question 34

How can complience by minimised in a RCT?

Answer 34

Simplified instructions
Patients can ask any questions
Made simple and accessible for patients
monitored by blood tests and urine samples

Question 35

How is a RCT ethical?

Answer 35

Unknown which drug is better
Pursuit of knowledge for the good of the general population
Ethical recruitment- no unethical exclusions
Valid consent- participants given sufficient knowledge, cooling off period, ability to withdraw
volunteers

Question 36

MEDICAL ROLE PRINICIPALS?

Answer 36

Do good, do no harm let the patient decide, be fair

Question 37

What is a systematic review?

Answer 37

Compilation of primary studies