Exam 2

Question 1

Exposure

Question 2

Outcome

Question 3

point prevelance

Answer 3

number of people with an event at a specific time / whole population

Question 4

period prevelance

Answer 4

people who develop disease (including all that died or left) / average pop at beg and end or population size at middle

Question 5

population at risk

Question 6

cumulative incidence

Answer 6

number of new cases / total number of people at risk

Question 7

incidence rate

Answer 7

number of new cases / number of people at risk * time frame

Question 8

person-time

Answer 8

sum of time at risk in each cohort (observed until outcome, censoring occurs)

Question 9

proportion

Answer 9

numerator included in the denominator

Question 10

rate ratio

Answer 10

compares the incidence rates of two groups

Question 11

stable population

Answer 11

limited number people exiting and entering the group over the time period

Question 12

unstable population

Answer 12

people leave, die, opt out often

Question 13

incidence

Answer 13

new cases

Question 14

prevalent cases

Answer 14

all current cases

Question 15

Disease duration

Answer 15

time with disease

Question 16

study midpoint

Answer 16

halfway during the study

Question 17

recurrent outcomes

Answer 17

an outcome that can occur more then once in the same individual

Question 18

morbidity

Answer 18

state of having a disease

Question 19

mortality

Answer 19

number of deaths

Question 20

burden of disease

Answer 20

measures impact of health problems in terms of cost, mortality etc.

Question 21

Mortality rate

Answer 21

percentage of population that has died in that specific time period

Question 22

cause-specific mortality

Answer 22

percentage of the population that have died due to a specified cause

Question 23

group-specific mortality

Answer 23

percentage of a specific population of interest that has died over a specified period

Question 24

proportionate mortality

Answer 24

percentage of total deaths due to a specific cause

Question 25

case fatality rate

Answer 25

number of deaths from given disease / number of people who have the given disease

Question 26

descriptive study

Answer 26

qualitatively describes -- good for making hypothesis

Question 27

case report

Answer 27

weakest level of evidence, good at new and rare diseases, sort of surveillance

Question 28

case series

Answer 28

more patients, focused on characteristics of groups, retrospective or prospective, common diseases, number 2

Question 29

hypothesis

Answer 29

state exposure and outcome relationship, magnitude and direction, testable

Question 30

analytic study design

Answer 30

tests hypotheses -- observational and experimental

Question 31

ecologic

Answer 31

group level data are used for exposure outcome relationships, single point of time, cheap + easy, weak

Question 32

aggregate

Answer 32

group level, environmental measures

Question 33

unit of analysis

Question 34

aggregation bias

Answer 34

bias that occurs because of an association between variables that does not exist at an individual level

Question 35

cross sectional study

Answer 35

number 3, snap shot of population at a single point of time, exposure and outcome at the same time, participants sampled regardless of exposure status

Question 36

target population

Answer 36

complete set of people to whom we want to apply to the study

Question 37

study sample

Answer 37

a subset of target population assumed ot be representative of target population

Question 38

exchangeability

Answer 38

if the disease experience would be the same for exposed if they were unexposed

Question 39

reverse causation bias

Answer 39

outcome is a mistake as the cause of the exposure

Question 40

case control

Answer 40

participants are selected on whether they have the outcome,

Question 41

primary study base

Answer 41

recruit from an existing sample -- nested, incidence outcomes

Question 42

secondary study base

Answer 42

not well known, cases are identified , prevalent outcomes

Question 43

control selection

Answer 43

population, neighborhood, hospital, friend, dead

Question 44

density sampling

Answer 44

define a risk set (everyone at risk at a specific time), case and controls are matched, primary base,

Question 45

case-cohort sampling

Answer 45

primary base, select all cases, select at beginning of cohort, number of controls doesn't have to be equal, cases can also be controls

Question 46

cumulative sampling

Answer 46

secondary study bases, sample at end of follow up

Question 47

cohort study

Answer 47

best other than randomized trials, follow a group at risk and compare development of outcome, can be open or closed, concurrent or non-concurrent

Question 48

base population

Answer 48

primary or secondary

Question 49

self-selected exposure

Question 50

closed cohort

Answer 50

no new members, time scale is same for all, defined by an event

Question 51

open cohort/dynamic cohort

Answer 51

defined by a state, can exit enter and re-enter, duration can vary

Question 52

cohort membership

Question 53

prospective cohort study

Answer 53

investigator begins at the beginning of the study

Question 54

non-concurrent cohort study

Answer 54

begins at end of the study and works backwards

Question 55

follow-up

Answer 55

time between beginning and end

Question 56

special exposure cohort

Answer 56

based on a specific exposure status, exam other exposures

Question 57

general population cohort

Answer 57

independent of exposure status (examine many exposures)

Question 58

baseline

Answer 58

start of follow-up time

Question 59

active follow-up

Answer 59

frequent contact with participants

Question 60

passive follow-up

Answer 60

linkage of existing registries