Health screening Flashcards
(20 cards)
Define overdiagnosis.
Correct diagnosis of a disease, but the diagnosis is irrelevant because the disease will never cause symptoms within the person’s lifetime
Define overtreatment.
Unnecessary treatment which does not improve health
What is meant by the population paradox in health screening?
The more overdiagnosis and overtreatment that results from screening, the more people believe the screening was of benefit to them, and the more popular it becomes
What are the 4 sections of the Wilson and Jungner criteria for health screening?
Disease
Test
Treatment
Programme
What are the 3 factors in the disease section of the Wilson + Jungner criteria?
Important health problem
Natural course of the disease is understood
Latent or early symptomatic stage exists
What are the 2 factors in the test section of the Wilson + Jungner criteria?
Suitable (simple, safe, precise + validated)
Acceptable
What are the 3 factors in the treatment section of the Wilson + Jungner criteria?
Accepted treatment
Facilities for diagnosis, and treatment
Agreed policy on whom to treat
What are the 3 factors in the programme section of the Wilson + Jungner criteria?
Case-finding should be a continuous process
Cost-effective
Accessible
Define sensitivity.
The ability of a test to correctly identify people who have the disease
Define specificity.
The ability of a test to correctly identify people who do not have the disease
Define positive predictive value.
The probability that someone with a positive test result actually has the disease
Define negative predictive value.
The probability that someone with a negative test result truly does not have the disease
What are the 3 main types of bias in health screening?
Healthy volunteer bias
Length time bias
Lead time bias
Define length time bias.
Those with long pre-clinical phase are more likely to be detected by screening & usually have better prognosis (less aggressive disease)
Define lead time bias.
Survival time for people with screening-detected disease appears longer because we make the diagnosis sooner
Which organisation advises ministers and the NHS about all aspects of population screening?
National Screening committee (NSC)
Cervical screening is offered to which age groups and how often?
Ages 25 - 49, every 3 years
Ages 50 - 64, every 5 years
At what age is breast screening offered?
50 years old
At what age is bowel screening offered and how frequently?
Ages 60 - 74 years old, every 2 years
AAA screening is offered to men from what age?
65 years old
