study design

Question 1

what are the steps involved in evidence based medicine

Answer 1

asking focused questions
finding the evidence
critical appraisal
making a decision
evaluating performance

Question 2

what is a stucture used to ask specific questions when evaluating healthcare

Answer 2

PICO

Population
Intervention
Comparator
Outcome

Question 3

describe the hierarchy of evidence in studies

Answer 3

Hierarchy 1a (level A)
Systematic reviews or meta analysis of randomised controlled trials *gold standard*

Hierarchy 1b (level A)
At least 1 randomised controlled trial

Hierarchy 2a
At least 1 controlled trial without randomisation

Hierarchy 2b
At least 1 other type of quasi-experimental study

Question 4

what is the purpose of a critical appraisal

Answer 4

to assess and consider validity, reliability and applicability.

It should be done so that you can apply results to your own patients, provide your patient’s the best possible evidence when communicating risk and to remain professional.

Question 5

what is validity

Answer 5

Validity is defined as the extent to which a concept is accurately measured in a quantitative study.

Question 6

what is reliability?

Answer 6

how consistent results are. If the experiment was repeated again, would the same/similar results be seen?

Question 7

what is applicability

Answer 7

is how relevant a study is to clinical medicine.

Question 8

what are good qualities of a study

Answer 8

Have random allocation of participants to interventions (reduces bias/confounding variables)

Have outcome measures for at least 80% of participants

Show causation rather than association

Question 9

what are the categories of observational studies?

Answer 9

descriptive
descriptive and analytical
analytical

Question 10

name types of descriptive studies?

Answer 10

case reports or series

ecological studies

Question 11

what are ecological studies, what do they show?

Answer 11

Use routinely collected data to show trends in data and thus is useful for generating hypotheses.

Shows prevalence and association, cannot show causation.

Question 12

describe what a cross sectional study is

Answer 12

find associations at that point in time by seeing who has /hasnt got the disease

They are used to generate hypotheses

Question 13

what are the limitations of a cross sectional study

Answer 13

but are prone to bias and have no time reference.

Question 14

what are case control studies

Answer 14

These are retrospective studies that take people with a disease and match them to people without the disease for age/sex/habitat/class etc and study previous exposure to the agent in question.

Question 15

what are the benefits of a case control study

Answer 15

It is quick and inexpensive

Question 16

what are the limitations of a case control study

Answer 16

Retrospective:

shows only associations
data may not be reliable due to problems with patient’s memories.

Question 17

what are cohort studies

Answer 17

Studies a population over time to see whether they are exposed or not and the consequences of that

Question 18

what are the advantages of a cohort study

Answer 18

possible to distinguish preceding causes from concurrent associated factors.

There is a lower chance of bias

absolute, relative and attributable risks can be determined.

as its perspective causation can be determined

Question 19

what are the disadvantages of a cohort study

Answer 19

Requires controls to establish causation.

Question 20

what type of study is a RCT

Answer 20

experimental/interventional

Question 21

what are the pros of a RCT

Answer 21

shows causation

bias and confounding factors are limited

Question 22

what are the cons of a RCT

Answer 22

expensive and have volunteer bias

Question 23

what are the cons of a non randomised trial

Answer 23

extremely Bias

Question 24

what is an independent variable

Answer 24

a variable that stands alone and isn’t changed by the other variables you are trying to measure. For example, someone’s age might be an independent variable

Question 25

what is a dependant variable

Answer 25

a variable that is dependent on the independent variables

Question 26

what criteria should be evaluated when establishing causality

Answer 26

Consistency
Strength of association
Specificity (single cause for a single effect)
Dose-response relationship
Temporal relationship
Biological plausibility
Coherence with existing theories
Altered by experimentation

Question 27

in terms of independent variable (IV) and dependant variable (DV), describe the different types of causes

Answer 27

Where the IV is necessary for the DV
Where exposure to the IV is sufficient to cause the DV
Where the IV contributes to the DV.

Question 28

what is a systematic review

Answer 28

A review of a clearly formulated question that uses symptomatic and explicit methods to identify, select and critically appraise relevant research, and to collect and analyse data from the studies that are included in the review.

Question 29

what is a meta analysis

Answer 29

where statistical methods may be used to analyse and summarise the results of the included studies.

Question 30

how can meta analysis results be shown graphically

Answer 30

It can be graphically represented as a forest plot.

Question 31

define qualitative research

Answer 31

Qualitative research involves collecting and analyzing non-numerical data to understand concepts, opinions or experiences.

Question 32

define quantitive research

Answer 32

Quantitative research means collecting and analyzing numerical data to describe characteristics, find correlations, or test hypotheses.

Question 33

what are the types of qualitative research

Answer 33

Ethnography
Interviews
Documentary or thematic analysis

Question 34

define ethnography

Answer 34

emerging oneself in a particular lifestyle or group

Question 35

what are the problems associated with qualitative data

Answer 35

Interactive kinds: over-analysis of oneself using existing theories

Meaning imposition: not truly understanding what someone else is thinking

Crisis of representation: research cannot capture lived experiences

Reflexivity: personal interpretations of data

Generalisation