Disease screening Flashcards
what is screening
The application of a test, examination or other
procedure to the asymptomatic population to
distinguish between
in a punnet square, who has a disease
TP and FNs
what do you want a screening test to have
high sensitivity
what is sensitivity
TP/TP+FN
what are 4 sources of bias in screening
- lead time bias
- length time bias
- selection bias
- overdiagnosis bias
what is lead time
time between screening and time it would have been found without screening
what is length time bias
more slow cancers will be more likely to be found by screening
what will screening find more of, fast or slow cancer
slow
what is the selection bias
those that opt for screening also likely have better health behaviors and will appear to live longer
what are 4 cons of screening
- false positives -scary
- false negative - miss it
- discomfort
- labelling
what is pop-based screening
Population-based screening is where a test is offered systematically to all individuals in the defined target group within a framework of agreed policy, protocols, quality management, monitoring and evaluation
what is case finding
Opportunistic case-finding occurs when a test is offered to an individual without symptoms of the disease when they present to a health care practitioner for reasons unrelated to that disease
what is breast cancer screening effect
25% reduction in
mortality with regular
screening in 50-69
year olds
what is cervical cancer screening effect
Incidence reduced by
up to 80% with
regular screening
what is colorectal screening effect
16% reduction in mortality with regular screening using FOBT; 20% reduction in incidence with regular screening
what is mammography screening reccomendation
screen women 50 and up
what is MRI screening reccomendation
high risk women 39 and up
what is breast exam screening reccomnedation
not reccomended for women or clinically
what are present cervical cancer guidelines
start at 21 and get one every 3 years
what are special cervical screening categeories
HIV - annually dysplasia - anually pregnant - same WSW - same and WSM total hysterectomy - stop subtotal - keep it up
what is colorectal test
fecal occult blood test - if fine do each 2 years
what is colorectal test for those with first relative
colonoscopy at age 50 or 10 years before the relative had it
