Lecture 49/50 - Epidemiology 1 & 2 (studies) Flashcards
What is a population
a group of individuals (N > 1)
closed population
once starts, no one is added
loss due to death or no follow-up
open population
can take or lose new members over time
what are characteristics of measuring disease
- animal/person
- place
- time
disease frequency
occurence of health outcomes, like disease/death, in a population
the hierarchy of evidence is relevant to
clinical setting and reduction of bias
what are the categorizations of epidemiological studies
- descriptive
- analytical (observational and experimental)
descriptive study
search for patterns based on animal, place, or time to inform determinants of disease
analytical study
examine etiology and causal associations
observational - look at disease causation
experimental - look at therapeutic, intervention, and prevention
exposure
factor that may be associated with outcome of interest
*independent variable
Randomized control trials
experimental study where an exposure is assigned or modified
- include an intervention and control group
- clinical or community trials
T/F: RCT is the gold standard for evaluating the efficacy of therapeutic and preventive interventions
TRUE
placebo effect
beneficial and attributable to the expectation that the regimen will have an effect in non-life-threatening conditions
what are the benefits of randomization
- Facilitate groups are comparable
- reduces risk of selection bias
- most powerful method of eliminating confounding variables
cohort study
measures occurence of disease after exposure
exposed and unexposed study
source population
who we want to make inferences about
T/F: cohorts can be chosen based off pro/cons/advantages/disadvantages
TRUE
prosepective cohort
concurrent study
retrospective cohort
historic study
what are the advantages of cohort studies
- incidence and risk can be estimated
- temporal sequence of events can be verified
- more flexibility in exposure measurements
- may be less vulnerable to some types of bias
what are the disadvantages of chort studies
- require many individuals if outcome is rare
- long period of observation could delay results
- can only evaluate exposures at beginning
