Epidemiology and Stats OME

Question 1

define primary vs secondary vs tertiary prevention

Answer 1

primary: prevent onset of dx (norm to HTN)
secondary: prevent progression of dx (HTN to MI)
tertiary: prevent complications of progression (MI to CHF)

Question 2

examples of primary/secondary/tertiary prevention

Answer 2

primary (least expensive): eat well, exercise, stop smoking, limit etoh use, vaccinations
secondary: screening (sensitive, allows for false positives so as to limit missing dx), medication intervention
tertiary (most expensive): treatment of disease

Question 3

define “number needed to treat”

define “number needed to harm”

Answer 3

number of times something must be done to obtain benefit

number of times something must be done to cause harm/see a complication

Question 4

what are the 4 cancers commonly screened for? how and when?

Answer 4

colon: begin at 50yo or 10 yrs previous to family member, colonoscopy q10yr, flex sig q5yr + fecal occult stool card q3ry, fecal occult stool card q1yr, stop at 75-85yo
cervical: start at 21yo regardless of sexual history, Pap test q3yr, stop at 65yo
breast: start at 50yo, mamm q2yr, stop at 75yo
lung: 55-80yo in pts w/ 30pyears but quit less than years ago, CT of chest, stop at 80yo or reached 15 years of cessation

Question 5

what cancers are no longer routinely screened for?

Answer 5

prostate (annual rectal exam)

ovarian (CA-125 level)

Question 6

3 major medical diseases that are screened for?

Answer 6

AAA (M): >65yo w/ smoking history, abd US
Osteoporosis (F): >65yo, DEXA scan, bisphosphonate + VitD + Ca
Hep C: born 1945-1965 (baby boomers), Hep C antibody test

Question 7

4 generalized medical diseases that are screened for?

Answer 7

HIV: anyone, ELISA test
HTN: anyone every visit, two consecutive high BP within 2w
DM: A1C if pt has HTN, glucose tolerance test OR two consecutive elevated fasting glucose lvls
hyper-lipid: M > 35yo, F > 45yo, M or F > 20yo with known cardiovascular risk

Question 8

what studies have no intervention? intervention?

Answer 8

none = observational (just watching, not intervening)
intervention = experimental

Question 9

what does a longitudinal study observe?

Answer 9

change in prevalence

Question 10

what are case-control studies?

Answer 10

retrospective, starts with dx’d people and asks what their exposure was
- uses OR (odds ratio)

Question 11

what are cohort studies?

Answer 11

prospective, starts with exposed and follows them to see if dx develops
- uses RR (relative risk)