Study Designs Beyond RCTs

Question 1

observational studies

Answer 1

researcher is documenting a natural occurring relationship

Question 2

observational studies can be

Answer 2

descriptive or analytical

Question 3

interventional studies

Answer 3

researcher actively performs an intervention in some or all participants

Question 4

descriptive studies

Answer 4

describing data on one or more characteristics of a group
does not focus on reasons for occurrence
focus on novel/unusual signs, symptoms or events

Question 5

analytical studies

Answer 5

tests a hypothesis and establishes causal relationships between two variables

Question 6

prospective studies

Answer 6

the outcome has not occurred when the study starts
participants followed over a period of time

Question 7

retrospective studies

Answer 7

the outcome has already occurred in each individual by the time they are enrolled in the study
data collected from records

Question 8

what type of study:

investigator assigns exposure?

when they don’t?

Answer 8

yes - experimental

no - observational

Question 9

what type of study:

if the study describes the characteristics of a sample?

Answer 9

yes - descriptive study

Question 10

what type of study:

if the study analyzes relationship between 2 variables?

Answer 10

analytical study

Question 11

for observational trials:

sampling determined based on outcome?

Answer 11

case control

Question 12

for observational trials:

sampling determined based on exposure?

Answer 12

cohort

Question 13

for observational trials:

sampling without regard to outcome/exposure?

Answer 13

cross sectional

Question 14

which study is the first step into a new area of research?

Answer 14

descriptive studies

Question 15

methods of collecting descriptive studies

Answer 15

surveys
cross sectional studies
observation
case report
case series

Question 16

strengths of descriptive studies

Answer 16

quick and cheap
allows for analysis of facts, in depth understanding
both qualitative and quantitative methods

Question 17

weaknesses of descriptive studies

Answer 17

cannot use statistical tools
observer effect
bias
cannot establish causative relationships

Question 18

descriptive statistics

Answer 18

measures of central tendency
measures of dispersion
measures of frequency distribution
tables and charts

Question 19

causal inference

Answer 19

drawing conclusion that a specific treatment was the cause of the effect

Question 20

observational analytical trials only establish _______________ while interventional analytical trials only establish _________________

Answer 20

association

causation

Question 21

case report observes ______________ while case series observes _________________

Answer 21

a single person

multiple patients

Question 22

advantages of case report/series

Answer 22

detailed
identify undocumented rare/new diseases or adverse effects

Question 23

disadvantages of case report/series

Answer 23

bias
no information on disease frequency
small number of patients

Question 24

cross sectional studies

Answer 24

identify prevalence of exposure/outcome at a snapshot in time
retrospective and observational

Question 25

survey research

Answer 25

cross sectional study study the prevalence, distribution, and relationships of sociologic and psychological variables

Question 26

observational analytical studies

Answer 26

no randomization analyze associations between exposures and outcomes by observing subjects in real world settings

Question 27

theory

Answer 27

a set of statements/principles devised to explain group of facts/phenomena

Question 28

types of analytical observational studies

Answer 28

cohort cross sectional case control

Question 29

case control studies

Answer 29

association between disease states and previous exposure to risk factors

Question 30

appropriate use for case control studies

Answer 30

risk factors for rare conditions contact trace original point in outbreak

Question 31

case control studies cannot establish a

Answer 31

casual relationship

Question 32

cohort studies

Answer 32

group of subjects, initially free of study outcomes, followed over time from an exposure to one or more outcomes

Question 33

cohort studies determine association between

Answer 33

risk factors and subsequent development of disease states

Question 34

cohort studies are useful in investigation of

Answer 34

multiple outcomes after a single exposure and in study of rare exposures

Question 35

prospective cohort studies

Answer 35

subjects are followed prospectively to assess for development of disease

Question 36

advantages of prospective cohort studies

Answer 36

strongest type of observational study evaluate temporal relationship better control of data collection

Question 37

disadvantages of prospective cohort studies

Answer 37

cannot establish casual relationship expensive loss to follow up

Question 38

retrospective cohort studies

Answer 38

association of risk factors and subsequent development of disease states

Question 39

advantages of retrospective cohort studies

Answer 39

evaluate temporal relationship quick and cheap can calculate incidence and risk real world evidence

Question 40

Narrative review

Answer 40

summary of evidence on specific topic, qualitative "review articles"

Question 41

Systematic review

Answer 41

answers a defined research question summarize data from multiple studies, qualitative

Question 42

Meta-analysis

Answer 42

statistical methods that aggregate results of multiple studies, quantitative

Question 43

Meta-analysis types

Answer 43

pair wise: compare intervention to control (direct) network: multiple interventions, but one common (indirect)

Question 44

Publication bias

Answer 44

positive results more likely to be published

Question 45

Language bias

Answer 45

negative results less likely to be published in english

Question 46

Citation bias

Answer 46

positive results cited more frequently

Question 47

Clinical heterogeneity

Answer 47

variability in participants, interventions and outcomes

Question 48

Methodological heterogeneity

Answer 48

variability in study design, outcome measurement tools and risk of bias

Question 49

Statistical heterogeneity

Answer 49

variability in intervention effects being evaluated across different studies

Question 50

Poor overlap of confidence intervals indicates _____

Answer 50

statistical heterogeneity

Question 51

Forest Plot

Answer 51

visual of effect estimates and CIs for individual studies and meta-analyses area of block = weight

Question 52

PRISMA statement

Answer 52

evidence-based min set of items for reporting in systemic and meta-analyses

Question 53

PRISMA Flow diagram

Answer 53

describes how investigators went from all records identified via search strategy to most relevant studies

Question 54

% of variability

Answer 54

<25% = low inconsistency 50-75% = moderate >75% = high inconsistency

Question 55

Limitations of SLRs and meta-analyses

Answer 55

one number cannot summarize entire field file drawer problem important studies ignored