Session 6 - Screening Flashcards Preview

Semester 4 - HADSOC > Session 6 - Screening > Flashcards

Flashcards in Session 6 - Screening Deck (28):
1

Define screening

Screening is a systematic attempt to diagnose a previously unrecognised condition by the application of tests, examinations or other methods in a rapid, cheap way in order to distinguish between people who have the disease (or its precursor) and those who do not.

2

Give three different methods of detection of disease`

Spontaneous presentation
Opportunistic case finding
Screening

3

Outline the path of a positive screen result

Screen -> Positive screen -> Diagnostic tests -> Disease/no disease

4

Give four overall criteria which must be fulfilled before screening implemented

Disease
The test
Treatment
Programme

5

Give four points concerning disease which must be fulfilled before screening

Must be an important health problem
Epidemiology and natural history must be well understood
Must have an early detectable stage
Cost-effective primary interventions must have been considered and implemented

6

Give 6 points concerning the test which must be implemented before screening

Simple and safe
Valid and precise
Acceptable to the population
Distribution of test values must be know
Agreed cut off level for positive
Agreed policy on who to follow up further

7

Give three treatments criteria

Effective evidence based treatment must be available
Early treatment must be advantageous
Agreed policy on whom to treat

8

Give three programme criteria

Other options considered
Benefit shoudl outweigh physical/psychological harm
Facilities for diagnosis and treatment

9

What is a false positive

Screening programme refers well people for further investigation
Offered diagnostic testig for a condition they do not actually have

10

What is a false negative

Failure to refer people who do actually have disease
False reassurance for patients

11

What is sensitivity?

Draw out table
Proportion of people with disease who test positive
a/a+c

12

What is specificity?

The proportion of people without the disease who are test negative
d/b+d

13

What is PPV?

Positive predictive value
The probability that someone who has tested positive actually has the disease
a/a+b

14

What is a stong influencer of PPV?

Prevalence of disease
"If I test positive, does that mean I definitely have the disease?"

15

Can two tests have different PPV and same sens and spec?

Yes

16

What is negative predictive value?

Proportion of peoplee who are test negative who actually do not have the disease
d/c+d

17

Give two advantages of screening

Early detection of disease may improve outcome
Reassurance for those who test negative

18

Give four disadvantages of screening

False positive - Uneccesary tests
False negatives - False reassurance
False negative - Not offered dianositc testing they may benefit from
Expensive intervention that divert money from testing

19

What is lead time bias?

o Screened patients appear to survive longer, but only because they were diagnosed earlier

20

What is length time bias

o Screening programmes are better at picking up slow-growing, unthreatening cases than aggressive, fast-growing ones
o Diseases that are detectable through screening are more likely to have favourable prognosis, and may indeed never have caused a problem
 Curing people that don’t need curing?

21

What is selection bnias?

o Those who have regular screening are also likely to engage in other health behaviours that protect them from disease
o Similar to ‘healthy worker’ bias
o A RCT would help deal with this bias

22

Give three criticisms of screening programmes

Alteration of usual doctor-patient contract
Complexity of screening programmes
Limitations of screening (harm caused)

23

Give four examples of screening in UK

o Abdominal Aortic Aneurysm
o Bowel cancer
o Breast cancer
o Cervical cancer
o Diabetic Retinopathy
o Down’s syndrome
o Foetal anomalies
o PKU
o Sickle Cell and Thalassaemia

24

Give four categories of sociological critiques for screening

Structural critiques
Surveillance critiques
Social constructionist
Feminist critique

25

Give two structural critiques

o Victim blaming
 Individuals encouraged to take responsibility for their own health
 Are all equally able to do this?
o Individualising pathology
 What about addressing underlying material causes of disease?

26

Give a surveillance critique

o Individuals and populations increasingly subject to surveillance
o Prevention part of wider apparatus of social control?

27

Give a social constructionist critique

o Health and illness practices can be seen as moral – given meaning through particular social relationships

28

Give a feminist critique

Is screening targeted more at women?