Screening Flashcards
what is the process of screening
a process of identifying apparently healthy people who may be at an increased risk of a disease or condition
what is the purpose of screening
this is ultimately to save lives or improve the quality of life through early risk identification and tp reduce the risk of developing a serious condition or the bad complications that go along with it
what are some examples of screening in adults
AAA - one off scan Bowel cancer - every 2 years Breast cancer - every three years Cervical cancer - every three beats diabetic retinopathy - annually
requirements of the condition to be screened
important public health problem
natural history is understood
recognisable latent or early symptomatic phase
requirements of the test to be screened
simple, safe, precise and validated
acceptable
distribution of test results down and cut off defines
agreed policy on further diagnostic investigations
requirements of the treatment
effective and available
what are requirements of the screening programme itself
evidence from RTC that screening is effective/accurate
clinically, socially, ethically acceptable
cost effective
quality assured
what is sensitivity and how is it calculated
this is how well the test picks up having the disease
= the number of results where disease detected in people with the disease
/
number of people with the disease
x100
what is specificity and how is it calculated
this is how well the test detects not having the disease
= number of ‘normal’ results where the disease is not detected in people without the disease
/
the number of people without the disease
x100
what does high sensitivity and specificity show
- picks up most of the disease
- very few false negatives
- correctly detects no disease
- very few false positives
positive predictavice value, what is it and how’s it calculated
how reliable the test result which shows the disease is present
= number of people with the disease and a positive test result
/
number of people with a positive test result
x100
negative predictavice value, what is it and how’s it calculated
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
/
the number of people with a negative test result
x100
what are the benefits of screening
reduced disease incidence reduced disease mortality earlier, less radical treatment cost-effective overall population benefit
what are the harms of screening
false reassurance over-investigation and treatment anxiety longer period od morbidity with unaltered prognosis harm from the screening itself opportunity costs increased health inequalities
what was the outcome of the marmot review
Weighed the benefits and the harms of the breast cancer screening
there should e. ore communication of the associated harms and benefits to women
but is still very benefical
