POP Diagnosis & Screening

Question 1

Diagnostic Test

Answer 1

For pts presenting with symptoms - used to help establish the correct diagnosis.

Question 2

Screening Test

Answer 2

For pts in the ‘apparently’ healthy population.

Question 3

Types of screening: mass, multi-phasic, targeted, opportunistic

Answer 3

• Mass – whole population.
• Multi-phasic – many screening tests completed simultaneously.
• Targeted – groups with a particular exposure.
• Opportunistic – tested while at the Dr for unrelated purpose.

Question 4

Sensitivity

Answer 4

Sensitivity – proportion with the disease who test positive -> test +ve/total w disease. Remember snip.

Question 5

Specificity

Answer 5

Specificity – proportion without the disease who test negative -> test -ve/total free of disease. Remember spin.

Question 6

Positive predictive value

Answer 6

Positive predictive value – proportion with a positive test who have the disease -> true +ve/total with +ve test.

Question 7

Negative predictive value

Answer 7

Negative predictive value – proportion with a negative test who do not have the disease -> true -ve/total with -ve test.

Question 8

Lead time

Answer 8

Extra time during which you know you have the disease if it is diagnosed by screening rather than by clinical presentation.

Question 9

Length time

Answer 9

Screening tends to diagnose disease that is less aggressive than disease that presents clinically.