Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Public Health > Critical Numbers > Flashcards

Critical Numbers Flashcards

1
Q

What is confounding variable ?

A

Alternative explanation for an observed Association

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is the definition of a P value?

A

A P value tells you the probability that the results were due to chance

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What is length time bias?

A

Screening happens at regular intervals, people may be missed out due to timing of screening

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is leadtime bias?

A

Difference between knowing about disease and making a difference. One patient knows for two years longer that they have the disease, but both die at the same point.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What is selection bias?

A

People who choose to participate in screening may differ from general population e.g. may be at higher risk

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is a negative predictive value?

A

Proportion of people with a negative result who do not have the disease

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What is a positive predictive value?

A

Proportion of people who have a positive screening result who have the disease

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is the definition of specificity?

A

The proportion of people without the disease who are correctly excluded by the screening process.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What is the definition of sensitivity?

A

The proportion of people with the disease who are correctly identified by the screening process.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What is a false positive?

A

Someone who will be screened and shown to have the disease but on further testing do not appear to have disease

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What does secondary prevention aim to do?

A

Detect and treat a disease in its early stages

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What is the prevention the paradox?

A

A larger number of people at small risk of disease may contribute to more cases of the disease then a small number of people who individually at a greater risk

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What is the definition of prevalence?

A

Number of existing cases in a defined population at a defined point in time, divided by the total number of people in the population at that time

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What is the conclusion of a small P value?

A

Your sample results are unlikely when null hypothesis is true . Conclude there is a statistically significant effect

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

When is a p value statistically significant ?

A

P value < 0.05

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What information do confidence intervals provide ?

A

Direction of the effect.
Strength of the effect.
Variability of the effect

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What is the difference between statistically significant and clinically significant?

A

Clinically significant difference is one that is big enough to make it worthwhile difference. Statistical significance does not necessarily mean that the effect is clinically significant.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What is the process for hypothesis testing?

A

Set null hypothesis and alternative hypothesis. Carry out significance test. Obtain test statistic. Compare test statistic to hypothesised critical value. Obtain P value. Less than 0.05 reject null hypothesis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What is a cohort study?

A

What will happen? Specify factors associated with disease risk with exposure status determined.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What are the strengths of a cohort study?

A

Multiple diseases/outcomes can be studied. Multiple exposures can be studied. Demonstrates casual affects.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What are the weaknesses of a cohort study?

A

Need to deal with potential confounding affects. Not suitable for diseases with long latent periods

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What is a randomised controlled trial?

A

What will happen? Randomises participants then applies intervention

23
Q

What are the strengths of a randomised controlled trial?

A

Most convincing evidence of cause effect relationship. Insures treatment group similar at the start to prevent confounding.

24
Q

What are the weaknesses of randomised controlled trial?

A

Complicated by non-compliance and loss in the follow-up. Not always ethical or feasible

25
Q

What is a case control study?

A

What has happened? Retrospective direction of enquiry. Identify factors associated with the risk of disease

26
Q

What are the strengths of the case control study?

A

Relatively quick and inexpensive. Multiple exposures can be studied. Suitable for long latency diseases.

27
Q

What are the weaknesses of the case control study?

A

Only a single outcome can be studied. Exposure data must be available prior to study so limited potential to establish casual Effects

28
Q

What is a cross-sectional study?

A

What is happening? Measures prevalence, established risk factors and symptoms

29
Q

What are the strengths of a cross-sectional study?

A

Rapid feedback on current events. Quick and cheap

30
Q

What are the weaknesses of cross sectional study?

A

Confounding problems, and difficult to establish disease aetiology.
Selection bias

31
Q

What does standard error measure?

A

Measures variability of a sample estimate of the population parameter

32
Q

What is standard deviation?

A

Describes variability of observations in sample. The higher the standard deviation the more difficult to get representative data.

33
Q

How do you calculate a confidence interval?

A

To standard errors above and below sample mean

34
Q

What do the widths of the confidence interval depend on?

A

Sample size. Variability of data. Level of confidence.

35
Q

What are the two methods to compare risk?

A

Absolute risk.

Relative risk difference

36
Q

What is the definition of number needed to treat?

A

Number of people you need to treat in order to prevent one outcome

37
Q

What is the definition of number needed to harm?

A

Number of people you need to treat in order to cause one additional outcome.

38
Q

In critical appraisal what does RAAMbo stand for?

A

Representative
Allocated or adjusted
Accounted for
Measurement blind or objective

39
Q

What do you call the analysis of statistics and a systematic review?

A

Meta analysis

40
Q

What does P.I.C.O stand for?

A

Population/patient
Intervention
Comparison
Outcome

41
Q

Name five of the CASP checklist for randomised controlled trial?

A

Were all persons blind to study group?
What is their consistency between groups?
Were there enough participants?
Did the study ask a clearly focused question?
Was it an RCT?

42
Q

What is an ecological study?

A

Observational study, uses routine data from population looks at prevalence trends and correlation

43
Q

What is Association?

A

Existence of relationship between variables

44
Q

What is causation?

A

Existence of casual relationships between variables, cause must proceed affect

45
Q

What three things should you consider when doing a systematic review?

A

Validity
Reliability
Applicability

46
Q

What is a systematic review?

A

A review of clearly formatted questions that uses systematic methods to critically appraise evidence and to collect and analyse data from studies included in the review

47
Q

What is the Gini coefficient?

A

Statistical representation of Nations income distributed among residents.

48
Q

What are the two types of numerical data?

A

Discrete data and continuous data

49
Q

What is numerical data?

A

Data that has a measurement such as a persons height or weight

50
Q

What is discrete data?

A

Discrete data represents items that can be counted,

51
Q

What is continuous data?

A

Continuous data represents measurements, the possible values cannot be counted and can only be described using intervals on the real number line.

52
Q

What is categorical data?

A

Categorical data represent characteristics such as persons gender, marital status

53
Q

What is ordinal data?

A

Ordinal Data mixes numerical and categorical data. The data falls into categories but the numbers placed in the categories have meaning. For examples, rating a restaurant on a scale from 0 to 4

Public Health (3 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions