19 Evaluation of Screening Programs

Question 1

What is the #1 harm of screening?

Answer 1

False positives

Question 2

3 harms of screening

Answer 2

Screening tests are not perfect (false positives and false negatives)
Overdiagnosis
Overtreatment

Question 3

Overdiagnosis

Answer 3

Finding cancers that would never have presented clinically

Would have died of something else before it would have been a problem

Question 4

Overtreatment

Answer 4

Treating cancers that would not have lead to premature death

Question 5

Benefit to screening

Answer 5

Delayed death (decreased mortality rate)

Question 6

3 cancers we screen for in Canada

Answer 6

Breast
Colorectal
Cervical

Question 7

“Shift to the left”

Answer 7

Shift the frequency distribution of cancers from stages 2 and 3 to more of 1 and 2

Question 8

2 ways to evaluate screenin

Answer 8

RCTs

Cohort studies

Question 9

What are some things we use to decide if a screening program is worthwhile?

Answer 9

Disease must be important
Early treatment must be better than late treatment
Prevalence of preclinical disease is high enough to justify the cost of screening
Simple to administer
Acceptable (those being screened are going to cooperate)
Valid (provides a true measure of the attribute)
Yields reproducible results
Cost effective