Screening Flashcards

1
Q

What is screening?

A

• Screening is the process of identifying healthy people who may have an increased chance of a disease or condition.
• The screening provider then offers information, further tests and treatment. This is to reduce associated problems or complications.
(UK National Screening Committee 2018)

(Screening)… encompasses the whole system or programme of events necessary to achieve risk reduction. Screening is a programme, not a test.
(Raffle and Muir, 2009)

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

Why do screening?

A

Screening can:
• save lives or improve quality of life through early identification of a condition
• reduce the chance of developing a serious condition or its complications

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

What are the Wilson and Jungner criteria on the condition screened for for proposed screening?

A

The Condition
• Important public health problem
• Natural history understood
• Recognizable latent or early symptomatic phase

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

What are the Wilson and Jungner criteria on the test used for proposed screening?

A

The Test
• Simple, safe, precise and validated
• Acceptable
• Distribution of test results known and cut-off defined
• Agreed policy on further diagnostic investigations

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

What are the Wilson and Jungner criteria on the treatment used for proposed screening?

A

• Effective and available

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

What are the Wilson and Jungner criteria on the screening program proposed for a condition?

A
  • Evidence from RCTs that screening is effective/accurate
  • Clinically, socially and ethically acceptable
  • Cost effective
  • Quality assured
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What is the WHO screening criteria 2008?

A

• Response to a recognized need
• Objectives defined and evaluation planned at outset
• Defined target population
• Scientific evidence of effectiveness
• Programme should be comprehensive and integrated
• Quality assured, with systematic mitigation of risks
• Informed choice, confidentiality and respect for autonomy
• Programme should promote equity and access to screening
• The overall benefits of screening should outweigh the harm
“primum non nocere”

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

What are the current UK screening programs for adults?

A

Abdominal aortic aneurysm - M 65 one off
Bowel cancer - M+F 50-70 every 3 years
Breast cancer - F 50-70 every 3 years
Cervical cancer - F 25 - 64 every 3 years
Diabetic retinopathy - M+F Diabetics >=12 annually

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

What are the current UK screening programs during pregnancy?

A

Fetal anomaly
Infectious diseases
Sickle cell and thalassemia

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

What are the current UK screening programs for newborns and infant?

A

Physical examination
Blood spot
Hearing

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

How do you asses how good a screening test is?

A

• How does it perform?
– What is its sensitivity?
– What is its specificity?

• When applied to your population, how accurate are the results achieved?
– Positive predictive value
– Negative predictive value

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

What is sensitivity in regards to screening?

A

how well the test picks up having the disease

Number of results where disease detected in people with the disease
______________________________
Number of people with the disease

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

What does a highly sensitive test do?

A

– Picks up most of the disease

– Very few false negatives

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

What does a highly specific test do?

A

– Correctly detects no disease

– Very few false positives

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

What is positive predictive value?

A

how reliable is the test result which shows disease is present?

Number of people with the disease and a positive test result ______________________________
Number of people with a positive test result (ie showing disease)

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

What is negative predictive value?

A

how reliable is the test result showing disease is not present?

Number of people who do not have the disease and have a negative test result ___________________________________
Number of people with a negative test result (ie showing no disease)

17
Q

What are the benefits of screening?

A
  • Reduced disease incidence
  • Reduced disease mortality
  • Earlier, less radical treatment
  • Cost-effective
  • Overall population benefit
18
Q

What are the potential harms of screening?

A
  • False reassurance
  • Over-investigation and treatment
  • Anxiety
  • Longer period of morbidity with unaltered prognosis
  • Harm from screening test
  • Opportunity costs
  • Increased health inequalities
19
Q

Give a screening case study

A

Marmot Review: Benefit vs harm
of breast screening

Estimated for 10 000 women invited to screening:
• 681 cancers will be diagnosed, of which 129 (19%) will represent overdiagnosis.
• 43 deaths from breast cancer will be prevented

“UK breast screening programmes confer significant benefit and should continue…. Clear communication of [the associated] harms and benefits to women is of utmost importance”

“But for each woman the choice is clear: on the plus side screening confers a likely reduction in mortality from breast cancer because of early detection and treatment. On the negative side, is the knowledge that she has perhaps a 1% chance of having a cancer diagnosed, and treated with surgery and other modalities, that would never have caused problems had she not been screened.”

20
Q

What informed consent considerations should you make clear in screening?

A
  • Screening is not mandatory
  • Individuals should be provided with sufficient information about screening
  • Including: purpose, potential risks and burdens, pathway following test results
21
Q

Why are inequalities in screening important to consider?

A

• Ethical issue about equitable outcomes
• Legal requirements of Equality Act
• Increased cost of treatment, social care etc
• Reduced effectiveness of the screening
• Viability of the programme
• Less inequality may be better for everyone
Wilkinson, R., Pickett, K. 2009 The Spirit Level: Why More Equal Societies Almost Always Do Better. Allen Lane, London

22
Q

What parts of the equality act 2010 relate to screening?

A
  1. In carrying out this activity are we sure there is no unlawful discrimination?
  2. In carrying out this activity are we advancing equality of opportunity between those who have a protected characteristic and those who do not?
  3. In carrying out this activity are we fostering good relations between persons who share a relevant protected characteristic and persons who do not share that characteristic?
23
Q

Are inequalities in screening a considerable issue in the UK?

A

Yeah, there are noticeable discrepancy in screening and mortality rates in a variety of screening programs along the lines of deprivation

24
Q

What could cause inequalities in screening?

A
  • Identifying and inviting screening cohort
  • Acceptability of the test
  • Failure to make reasonable adjustments
  • Poor communication about the test results or the next steps in the programme
  • Prejudice leading to poor care
25
Q

When maximising engagement, what three populations should one consider?

A
a = eligible population
b = invited population
c = screened population

c is within b which is within a
so optimising the ratio of c to b and b to a is the main goal of maximising coverage and uptake

26
Q

What are the challenges of optimising coverage?

A
  • Change of address
  • Migrants
  • Travellers
  • Prisoners
  • Students
  • Trafficked people
27
Q

What are the challenges with optimising uptake?

A
  • Communication
  • Health literacy
  • Deprivation
  • Accessibility
  • Vulnerable groups
  • Minority ethnic groups
28
Q

Why does inequality in engagement matter?

A

• Equality of access is a legal duty
• Positivity rates are affected by low coverage in high
risk groups
• Less lives saved, poorer outcomes, more treatment
• Less faith in programme–downward spiral of engagement
• Reduced effectiveness threatens programme viability as the balance of harm versus benefit changes

29
Q

How can we improve engagement in vulnerable groups?

A

• Social marketing
• Everyone’s responsibility
• Qualitative research
• Known effective interventions
– Letter from GP; patient navigation; community mentors; “people like me”; languages; text reminders;
• Known barriers
– Uncertainty of benefit; fear of the screened-for condition; lack of time; disgust/discomfort/embarrassment;

30
Q

How do we know a screening programme is effective?

A

• Was the evidence there that it would work?
• Is it a systematic programme?
• Are the right people invited, getting screened, receiving quality treatment and follow-up?
• Is there good and effective clinical governance?
• Are the inequalities inherent in screening programmes being
systematically addressed?
• Is the programme regularly reviewed for ways to enhance its effectiveness or check that it is still viable viability? (changes to positivity rates, acceptability, epidemiology, new treatments etc)