Zusammenfassung der Ressource
3. COHORT & CASE CONTROL
- COHORT STUDIES
- cohort: group of persons sharing a common
characteristic (geogr, occup, sex, race,etc).
- 1. SOURCE POPULATION:se sacan entire or
random sample, se descartan enfermos YA con
outcome (exposure always preceed outcome) but
sometimes disease IS the exposure y se evaluan
muertes
- 2.FOLLOW OVER TIME
for new events,
calculating eg. risk v rate
- useful for studying uncommon or rare exposures
- measure incident cases -- can be PROSPECTIVE OR RETROSP., OPEN or CLOSE
- CASE CONTROL STUDIES
- for studying rare diseases(<10%).
Is INDUCTIVE (from effect to cause,
RETROSPECTIVE)--can really MIRROR a cohort
- 1. Define&select CASES (sick people)
- 2. Define&select CONTROLS (nonsick): restricted
source population from which cases arise
- MATCHING: for every case,
one control has the same
variable--should be only
STRONG factors
- 3. Measure&compare EXPOSURE PREVALENCE
- CANNOT use rate&risk, ONLY ODDS (the control is not representative of the population