Flashcards in Screening Deck (30):
List the 5 major screening programmes used on adults.
Abdominal aortic aneurysm
List the 3 screening programmes used during pregnancy.
Sickle cell thalassaemia
List the 3 screening programmes used on newborns & infants.
How often is bowel cancer screening carried out and in what age group?
Every 2 years
How often is breast cancer screening carried out and in what age group?
Every 3 years
How often is cervical cancer screening carried out and in what age group?
Every 3 years
20-60 (from June 2016, 25-64)
How often is AAA screening carried out and in what age group?
It is a one-off scan
How often is diabetic retinopathy screening carried out and in what age group?
Over and including the age of 12
What is screening?
A process of identifying apparently healthy people who may be at increased risk of a disease or condition
What is the main difference between screening and diagnostic testing?
A non-negative result on screening does not necessarily equal disease-free
What are the three major differences between healthcare and screening
Hope of benefit/Implied benefit
How would you assess the merits of a screening test?
How does it perform?
When applied to population, how accurate are results achieved?
- Positive/Negative predictive value
What is the SENSITIVITY a measure of?
HOW WELL THE TEST PICKS UP HAVING THE DISEASE
How would you calculate the sensitivity?
Number of results where disease detected in people with the disease
Number of people with the disease
What is the SPECIFICITY a measure of?
HOW WELL THE TEST DETECTS NOT HAVING THE DISEASE
How would you calculate the specificity?
Number of normal results where disease is not detected in people without the disease
Number of people without the disease
What can you say about a highly sensitive test result?
Picks up most of the disease
Very few false negatives
What can you say about a highly specific test result?
Correctly detects no disease
Very few false positives
What is a positive predictive value?
How reliable the test result is in showing that the disease is present
How would you calculate the positive predictive value?
Number of people with the disease and a positive test result (i.e. showing disease presence)
Number of people with a positive test result (i.e. showing disease presence)
What is a negative predictive value?
How reliable the test result is in showing that the disease is not present
How would you calculate the negative predictive value?
Number of people who do not have the disease and a negative test result (i.e. showing no disease presence)
Number of people with a negative test result (i.e. showing no disease presence)
What can the positive and negative predictive values be affected by?
List some of the advantages associated with screening.
Reduced disease incidence
Reduced disease mortality
Earlier, less radical treatment
Overall population benefit
List some of the disadvantages associated with screening.
Over-investigation and treatment
Longer periods of morbidity with unaltered prognosis
Harm from screening test
What is the 'gold standard' in measuring the effectiveness of screening?
Randomised controlled trial
Is screening mandatory and do you as a physician need consent to carry it out?
No, it is not mandatory and yes, informed consent must be given prior to screening being carried out
How would you calculate screening coverage in a population?
Screened population / Eligible population
How would you calculate screening uptake of a population?
Screened population / Invited population