epidemiology intro

Question 1

basics of epidemiology

Answer 1

study of distribution and determinants of health related states or events in specified populations and application of this study to control health problems

Question 2

why observe and screen pop.

Answer 2

Risk estimates, relevance of interventions, accuracy of estimates, comparisons, increased screening increases incidence rate but can decrease mortality

Question 3

epidemiology triad

Answer 3

time(day, year, ect), place(home, locality, environmental and socioeconomic), person(age, sex, eco status, behaviour ect)

Question 4

exposure and outcome

Answer 4

exposure- exposure to supposed cause of outcome or possession of characteristic that is a determinant of outcome

outcome- possible results that can stem from exposure to a causal factor or from preventative interventions, identifiable changes in health status

Question 5

random control trial when can’t you use it

Answer 5

opinions, rare or dangerous(ethics), experiences, mortality and other things you can’t blind test

Question 6

RCT studies

Answer 6

observational, descriptive and analytical hypothesis generating
interventional studies are experimental usually RCT

Question 7

Cross sectional studies basics and uses

Answer 7

get a sample and gather all exposure and outcome data at once
health service planning, resource allocation, can measure changes if conducting repeat cross sectional studies

Question 8

cross sectional study advantages

Answer 8

QCE(quick cheap easy),
measure multiple exposures and outcomes
no loss follow up
generate and test hypotheses

Question 9

cross sectional disadvantages

Answer 9

standardise measurements
bias responder and recall
associations difficult to interpret
not for rare diseases, short duration or emergent events

Question 10

point prevelance

period prevelance

Answer 10

no. existing cases/total at risk pop.
at a given point
period prevalence includes new and existing cases not best to use

Question 11

cohort studies basics

Answer 11

enrol at risk group and measure exposure status and follow over time

Question 12

cohort study advantages

Answer 12

good for rare exposures, measures more than one outcome, clear temporal relationship(relationship involving time), prospective study minimises bias, ethical and legal

Question 13

cohort study disadvantages

Answer 13

not good for rare outcomes, retrospective relies on good records, bias if follow exposed group more closely, prospective slow and expensive and loss of follow up

Question 14

cumulative incidence

Answer 14

no. new outcomes/people at risk

over given time at risk

Question 15

incidence rate

and benefits

Answer 15

no. new cases/person-at time risk

good for common diseased open population

Question 16

case control study basics

Answer 16

compare exposure history between groups-retrospective

start with outcome and look for exposures

Question 17

case control study advantages

Answer 17

QEC, rare outcomes, multiple exposures can be measured, good for diseases with long latency period

Question 18

case control study disadvantages

Answer 18

select controls, recall bias, not good for rare exposures, can’t create incidence rates

Question 19

confounder

Answer 19

variable associated with outcome and exposure but doesn’t lie on the causal pathway

Question 20

chance, bias, confounding

Answer 20

representative sample, statistical inferences, valid measures