cman 380 exam 2

screening?

• process of using clinical tests and/or examinations to identify patients who require additional health-related interventions

  • testing people who are at risk BUT are asymptomatic

• key component of secondary prevention

is a screening diagnostic?

no!

• screen a subset of the population who may be at risk

what is USPSTF?

US Preventive Services Task Force

• uses clinical research and evidence-based preventative care to recommend screenings

does USPSTF fall under HHS?

No, but HHS supports USPSTF

• USPSTF falls under Agency for Healthcare Research and Quality (which is under HHS)

USPSTF grading

a: recommends

b: moderate

c: selectively offering

d: against the service

i: evidence is insufficient

criteria for making a screening program

1.The disease problem is significant and potentially manageable, i.e., you can do something about it once it is identified.

2.The screening technique is valid; i.e., the screening results can be confirmed by other diagnostic procedures.

3.The screen technique is reliable, i.e., it gives a consistent result.

4.There will be a sufficient # of cases to make the screen worthwhile, i.e., the prevalence of the disease is relatively high.

5.The cost is reasonable; i.e., the cost-benefit ratio must be favorable.

6.The screening technique is acceptable; i.e., the public will want to participate.

7.The follow-up services and facilities are adequate. And we have an ethical responsibility to refer persons discovered to have the disease to appropriate sources for care.

***if 1 of 7 is missing, do not test

other factors to consider in selecting a screening tool

• cost vs benefit

• is it acceptable?

• test’s reliability and validity?

• easy to administer?

• does the test detect at an early stage?

• is the treatment for the disease being screened for available?

how to select a screening test?

must be valid & reliable

• validity: can correctly distinguish

  • sensitive: correctly identifies those WITH disease

  • specific: correctly identifies those W/O disease

• reliable: consistent results over time & between examiners

sensitivity example

• sensiTivity = sensitive to the Truth

• if test has 90% sensitivity, test can correctly identify 90 of 100 people with the disease

• other 10 people will appear negative for the disease (false negative)

specificity example

• speciFicity = speciFies the False

• if a test has 90% specificity, if 100 healthy people are tested then 90 healthy people will be found to be disease free

• other 10 people will appear positive for the disease (false positive)

when is sensitivity prioritized?

• disease is serious

• treatment is effective & available

• high risk of infectivity if individuals are not treated

• subsequent test (next option) is cheap and low-risk

when is specificity prioritized?

• treatment is difficult

• subsequent tests is expensive and risky