Biostat ch 2 definitions

Question 1

Observational Study Design

Answer 1

can be used to alert the medical/public health community to emerging health issues, generate/test hypotheses, and asses specific associations

Question 2

Experimental Study Design

Answer 2

test hypotheses, evaluate the effect of the intervention, determine causality

Question 3

Cohort

Answer 3

share common characteristics and are followed over time

Question 4

Confounding Variable

Answer 4

distorts the relationship between the risk factors and the outcome

Question 5

Cross-Sectional

Answer 5

at a single point in time

Question 6

Incidence

Answer 6

number of new cases over a period of time

Question 7

Prevalence

Answer 7

proportion of individuals with the condition (new and existing) at a single point in time

Question 8

Prospective

Answer 8

data collected going forward in time

Question 9

Retrospective

Answer 9

data collection looking back in time

Question 10

Case Report

Answer 10

detailed report of specific features of case

Question 11

Case Series

Answer 11

report on common features of a small number of cases

Question 12

Case Series Example

Answer 12

Gottleib studied 5 young homosexual men with rare form of pneumonia and other unusual infections. Start of AIDS research

Question 13

Cross-Sectional Study

Answer 13

conducted at a single point in time, data collected through surveys, non-randomized, estimates prevalence of risk factors, diseases, practices, or opinions, can make comparisons between groups

Question 14

Cross-Sectional Study Example

Answer 14

Is there an association between diabetes and cardiovascular disease?

Question 15

Case-Control Study

Answer 15

participants identified and included in study based on the presence or absence of outcome of interest, cases have disease, controls are free of disease, compare cases and controls with respect to the proportions exposed, is there a statistically significant difference bt cases and controls with regards to exposure status?

Question 16

Case-Control Study Example

Answer 16

is there an association between sleep position and SIDS?

Question 17

Cohort Study

Answer 17

includes persons exposed and not exposed to risk factor at outset- usually persons are disease free, follow prospectively or retrospectively, can asses temporal relationship and calculate incidence, problem if disease is rare, bias is less of an issue than case-control

Question 18

Cohort Study Example

Answer 18

is there an increase in the incidence of CVD among those who have hypertension?

Question 19

Blinding

Answer 19

participant is unaware of their treatment status

Question 20

Double Blind

Answer 20

participant and outcome assessor are unaware of treatment status

Question 21

Intention-to-Treat

Answer 21

analytic strategy whereby participants are analyzed in the treatment group they were assigned regardless of whether they followed the study procedures completly

Question 22

Per protocol

Answer 22

analytic strategy whereby only participants adhered to the study protocol are analyzed

Question 23

Placebo

Answer 23

inert substance designed to look, feel, and taste like the active or experimental treatment

Question 24

Stratification

Answer 24

a process whereby participants are partitioned or separated into mutually exclusive or non-overlapping groups

Question 25

Prognostic Factor

Answer 25

a characteristic that is strongly associated with an outcome such that it could be used to reasonably predict whether a person is likely to develop a disease or not

Question 26

Efficacy

Answer 26

how the intervention performs under ideal conditions

Question 27

Effectiveness

Answer 27

how the intervention performs in the real world

Question 28

Randomized Control Trial

Answer 28

experimental study where patients are randomized to receive one of several comparison treatments

Question 29

Randomized Control Trial Example

Answer 29

is the new drug efficacious in reducing hyperlipidemia?