HADPOP

Question 0

Describe the two types of causality. And how do they help us?

Answer 0

Deterministic. Inevitable. It allows us to predict trends with certainty. It validates the hypothesis by observations.
Stochastic. Shows the likelihood of future events. It is an assessment of the hypothesis.

Question 1

Why do we undertake epidemiological studies?

Answer 1

To gain a perspective beyond that of the individual.
Asses population based risk.
Investigation causes of disease
Treating and preventing disease 
Evaluating drugs and interventions

Question 2

What is a population census?

Answer 2

A simultaneous recording of demographic data to all persons in a defined area.

Question 3

Size and structure of a population is affected by 3 things.

Answer 3

Births (trends of fertility)
Deaths (trends)
Migration

Question 4

What measures birth rate as the number of life births per 1000 population?

Answer 4

Crude Birth rate

Question 5

Define the general fertility rate (GFR)

Answer 5

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

Question 6

Describe the total period fertility rate.

Answer 6

Average number of children born to a hypothetical women in her
Lifetime.

Question 7

How do you calculate TPFR

Answer 7

Sum of current age - specific fertility rate

Question 8

How do we measure death rates?

Answer 8

Crude mortality rate or an age specific mortality rate

Question 9

Define fecundity

Answer 9

Physical ability to reproduce.

E.g. Sterilisation and hysterectomy (removing woman’s womb)

Question 10

Define fertility

Answer 10

Realisation of the potential for giving birth. Taking into consideration contraceptives and abortion.
Actual birth rates, from those that are capable of giving birth.

Question 11

Why can deaths be recorded wrongly, under the wrong diagnosis?

Answer 11

There can be coding errors.
E.g. Diabetes
May be listed as the cause of death but it may just be a contributing factor.

Question 12

What is artefactual variation?

Answer 12

Systematic variation. Where the data is altered due to a systematic reason, it occurs across a range of results not just one, and can be due to measuring incorrectly, having a consistent mistake,….

Question 13

Define incidence

Answer 13

Measuring new cases that have occurred.

Question 14

What type of study is useful to track and maintain epidemics?

Answer 14

Incidence surveys

Question 15

True/false

New events/ (person x time) = events per person

Answer 15

FALSE
Events per person PER YEAR
get rid of standard form

Question 16

Is prevalence a rate?

Answer 16

No it is a proportion, it is not calculated as per person per time.

Question 17

What kind of survey measures existing cases of a disease.

Answer 17

Prevalence

Question 18

In what situations does incidence rates increase or stay the same and prevalence in the population decreases?

Answer 18

When there has been a cure or there are lots of deaths from the disease.

Question 19

What variation does incidence rates not account for?

Answer 19

The individuals risk of disease. It is an average risk.

Question 20

True/false

Systematic variation can give clues on the aetiology of the disease?

Answer 20

True

Question 21

How do we measure the efficacy of 2 treatments?

Answer 21

Using an incidence rate ration
Incidence rate= absolute risk
Ratio=relative risk

Question 22

How to account for confounding factors?

Answer 22

Standardisation of the results.

Question 23

What ratio compared morbidity observed in a study population with the level of mortality expected?

Answer 23

SMR. Standardised mortality ratio

Question 24

An SMR of over 100% means?

Answer 24

There is a higher risk in the study population

Question 25

Define accuracy

Answer 25

How close the data is to the true value. Repeals would show the same results.

Question 26

Define validity

Answer 26

The extent to which a result is well founded and responds accurately to the real world. It is dependent on completeness and accuracy.
More debatable.

Question 27

Give some examples of observed epidemiological quantities.

Answer 27

Incidence, prevalence,IRR etc

Question 28

What is the observed value

Answer 28

The number that we actually go out and measure. This is subject to random variation.
E.g. The number of cases of meningitis at a gp surgery in feb was 4 . In March it was 1 and in April it was 10. The true or underlying tendency is cases a month.

Question 29

What is the hypothesis?

Answer 29

The hypothesis is s statement that an underlying tendency takes a particular quantitative result.

Question 30

How do we normally state the null hypothesis?

Answer 30

That there is no link between the exposure and the case.