Epideomology

Question 1

incidence

Answer 1

the rate at which new events occur in population

should not include cases that occured or were diagonosed eaelier

Question 2

prevalance rate

Answer 2

proportion of people in pop who have the ds in a sp period /point of time

Question 3

diff bw period and point prevalance

Answer 3

burden of ds

whether an outbreak is occuring or not

Question 4

pre test probabilities

Answer 4

sensitivity

specificity

Question 5

post test probabilities

Answer 5

positive and negative predictive values

Question 6

1-sensitivity=

Answer 6

false negative rate

Question 7

accuracy

Answer 7

true pos and neg/total screened patients

Question 8

selection bias

Answer 8

random,independent sample

samole not representative

Question 9

berkson bias type of

Answer 9

selection/sampling bias

Question 10

measurment bias

Answer 10

control group

Question 11

lead time bias

Answer 11

use life expectancy

Question 12

experimenter expectancy/

Answer 12

double blind:not to tell who is control and who is main

Question 13

design bias

Answer 13

parts of study do not fit together

random assignment

Question 14

confounding bias

Answer 14

unanticipated factors obscure results
combine results from multiple studies
metaanylasis

Question 15

recall bias

Answer 15

subjects cannot remember accurately

confirmatiin

Question 16

late look bias

Answer 16

severly ds individuals are not uncovered

stratify by ds severity

Question 17

pygmylion effect is

Answer 17

experimentor expectancy bias

Question 18

observational studies

Answer 18

case report
case series
cross sectional
case control
cohort

Question 19

cohort

Answer 19

risk factors vs non risk factors
prospective search for who gets the ds
(tell I,C not P)

Question 20

case report

Answer 20

n=1

Question 21

case series

Answer 21

n>1
features of ds can be ruled out
but no control

Question 22

cross sectional

Answer 22

tell about only prevalance

Question 23

case control

Answer 23

ds vs non ds
retrospective search of risk factors
tell C,not I,P

Question 24

analysing cohort study

Answer 24

RR

AR

Question 25

for analysing cross sevmctiinal studies

Answer 25

chi square

Question 26

phase 1

Answer 26

safety in healthy volunteers

Question 27

phase 3

Answer 27

efficacy and side effects

Question 28

phase 2

Answer 28

protocol and dose level,how to administer

Question 29

control groups

Answer 29

source of comparison to be certain that the experiment group is being affected by the intervention and not by other factors 1. placebo 2. std of care

Question 30

definitive trial

Answer 30

3

Question 31

double blind RCT

Answer 31

neither the subjects nor the researchers who is getting tt/placebo

Question 32

cross over study

Answer 32

all subjects receive intervention but at different times

Question 33

how ll u assess data from following observational studies 1. cross sectional studies 2. case control 3. cohort

Answer 33

1. chi square(ass of risk factor and ds) 2. odds ratio(many risk factors for single ds) 3. RR(single risk factors aff many ds)

Question 34

what does odds ratio tell?

Answer 34

how strong is the risk factor

Question 35

interpretation of NNT and NNH

Answer 35

1. how many people do u have to treat to stop one ds | 2. how many people do u have to expose to get one case

Question 36

Berksons bias

Answer 36

Selection or sampling bias created by selecting hospitalised patients

Question 37

Pygmalion effect

Answer 37

Describes researchers belief in the efficacy of treatment that can potentially effect the outcome Experimental expectancy