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Flashcards in Definitions Deck (46)
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1

What is a Census?

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

2

What is the Crude birth rate?

Number of live births per 1000 population

3

What is the General birth rate?

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

4

What is the Total period fertility rate?

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

5

What is an Incidence rate?

The number of new cases of the disease per 1000 people per year (or 1000 person–years)

6

What is Prevalence?

The amount of people who currently have the disease in a set population (with no time frame)

7

What is Incidence rate ratio?

Incidence rates of two separate populations, with varying exposure, can be compared to see if exposure causes certain diseases

8

What is a confounder?

Something that is associated with both the outcome and the exposure of interest, but is not on the causal pathway

9

What is Standardised mortality rate?

The number of observed deaths / Number of expected deaths x 100

10

What is Variation?

A difference between the ‘observed’ and the ‘actual’ value

11

What is the lower confidence interval?

value ÷ error factor

12

What is the upper confidence interval?

value x error factor

13

What is the P value?

States how likely the results in the study would have occurred by chance if the null hypothesis was true.

14

What is Bias?

Deviation of the results from the truth via certain processes

15

What is Selection bias?

Error due to systematic differences in the ways in which the two groups were collected

16

What is Information bias?

Error due to systematic misclassification of subjects in the group

17

What are the 2 types of Selection bias?

Allocation bias
Healthy worker effect

18

What are the 2 types of Information bias?

Recall bias
Publication bias

19

What is a Cohort study?

Recruiting disease free individuals and classifying them according to their exposure status. Followed up for extended periods, disease progress is monitored, and incidence rates are calculated

20

What is Internal comparison?

Have sub-cohorts within your original group and then compare exposed and unexposed within the cohort. Uses IRR

21

What is external comparison?

Have your exposed population compared against a reference population instead. Uses SMR

22

What is the Healthy worker effect?

Employed individuals are more likely to be healthy than unemployed individuals as they work

23

What is a Case control study?

Recruit disease-free (controls) individuals and diseased individuals (cases) and then exposure status is determined

24

What is Double blinding?

Patient and doctor don't which treatment they are on, removing any selection bias

25

What is the Bradford Hill criteria?

Strength of association
Specificity of association
Consistency of association
Temporal sequence
Dose response
Reversibility
Biological plausibility
Coherence of theory
Analogy

26

What is Clinical equipoise?

Reasonable uncertainty into which drug is better for the patient, so not subjecting patients to known less effective treatment

27

What is Ethical recruitment?

Recruitment for region where drug will take affect and no unethical exclusions from the trial

28

What is Valid consent?

Participants given sufficient knowledge, cooling off period, chance to ask questions, and ability to withdraw from trial at any point

29

What is Voluntariness?

No coercion or manipulation into entering the trial

30

What is a Systematic review?

A compilation of primary studies

31

What is a Meta analysis?

Provide quantitative synthesis of the primary studies used in the trial

32

What is the Fixed effects model?

Assumes the studies used are homogenous and any variation between data comes from within-study variation

33

What is the Random effects model?

Assumes the studies are heterogeneous and variation between data comes from within-study variation and between-study variation

34

What is Publication bias?

Studies are only likely to be published if results are statistically significant or have a large sample size. Funnel plots can determine Publication bias

35

How does a Forest plot display information?

Square size linked to weight in study
Diamond is overall measurement
Tips of diamond represent confidence intervals

36

What does it mean if the null value lies within the 95% CI?

The result may be due to chance, we cannot reject the null hypothesis.

37

What does it mean if the 95% CI excludes the null value?

The association is unlikely to be due just to chance.

38

What is reverse causality?

Possible that the cause-effect relationship exists, but in the opposite direction

39

What is the Henle Koch postulates?

Necessary - cause always precedes disease
Sufficient - cause alone leads to disease
Specific - cause absent in other diseae

40

Outline steps in RCT

Allocate
Follow up
Assess
Compare

41

What is the placebo effect?

Psychological benefit from being cared for, or differently, and being on a new treatment.

42

What are the types of outcome?

Patho physiological
Clinically defined
Patient focused

43

What are the features of an ideal outcome?

Appropriate/relevant
Valid and attributable
Sensitive and specific
Reliable and robust
Simple and sustainable
Cheap and timely

44

What is an explanatory trial?

An as treated analysis. The non compliers are excluded

45

What is a pragmatic trial?

Intention to treat analysis. Better indication of drug in real life as non compliers are kept in

46

What makes a clinical trial ethical?

Clinical equipoise (not knowing which treatment is better)
Scientifically robust
Ethical recruitment
Valid consent