Wk2- how much evidence is needed

Question 1

types of clinical questions

Answer 1

intervention- effectiveness of treatment
diagnostic- diagnostic tests, or presence/absence of signs and symptoms
prognostic- asking about the future
patient experiences/concerns- qualitative research to understand the why and how

Question 2

what is “just in case” information

Answer 2

information that is pushed out to you. usually when you’re not needed the information

Question 3

just in time information

Answer 3

creating a question and filtering through results to acquire information

Question 4

steps to creating an answerable question 4

Answer 4

1. identify a knowledge gap/ information need
2. classify the need for information as either intervention, diagnostic, prognostic or patients experience/concern.
3. clearly articulate required components from the PICO framework.
4. review question, seek feedback from others and refine work

Question 5

comparison in PICO is not used it what kind of questions?

Answer 5

prognostic

Question 6

qualitative research

Answer 6

inductive reasoning, where we move from specific –> general. focuses on the how and why of peoples actions

Question 7

quantitative research

Answer 7

deductive reasoning, general –> specific. typically the more reliable data, numerical.

Question 8

hierarchies of evidence

Answer 8

quality of evidence improves from the bottom to top
bottom areas, unfiltered information
top areas, filtered information

Question 9

list the hierarchy of evidence pyramid worst to best (7)

Answer 9

systematic reviews
critically appraised topics
critically appraised articles
RCT
cohort study
case control study
background information/ expert opinion

Question 10

level 1 evidence (best evidence) for intervention, diagnosis and prognosis?

Answer 10

a systemic review of level 2 studies

i: systematic review of RCT
d: systematic review of a study of test accuracy with
- an indecent blinded comparison
- a valid reference standard
-and defined clinical presentation
p: systematic review of a prospective cohort study

Question 11

level 2 evidence for intervention?

Answer 11

randomized controlled trial

Question 12

level 2 evidence for diagnosis

Answer 12

a study of test accuracy with an indecent blinded comparison. with a valid reference standard, amount consecutive persons with a defined clinical presentation

Question 13

level 2 evidence for prognosis

Answer 13

prospective cohort study

Question 14

list the hierarchies of studies strongest to weakest 6

Answer 14

1. randomized controlled trial (experimental) - analytical
2. cohort study (observational) - analytical
3. case-control study “ -analytical
4. cross sectional study “ -descriptive
5. ecological study “ -descriptive
6. case reports/series “ -descriptive

Question 15

case report/case series

Answer 15

-observational studies
-descriptive
-no comparison group
-no assigned exposure

report: description of a single patient/presentation that is unusual

series: combines multiple cases (people)

lower end of pyramid because its subject to opinion and bias

Question 16

what area of the study should you look at to identify what type of study design it is?

Answer 16

methods section

Question 17

cross-sectional study

Answer 17

-analytic or descriptive
-observational
-no assigned exposures
-comparison group
-obtain exposure and outcome data at the same time
-single point time snapshot (present)

Question 18

advantages of cross sectional studies 6

Answer 18

-quick and easy
-no follow up
-disease prevalence information at a specific time
-may suggest associations between outcome and exposure
-useful for public health planning/understanding -and for hypothesizes generation

Question 19

disadvantages of cross-sectional studies 4

Answer 19

-doesn’t tell us cause or effect
-it is only a snapshot of time
-potential for confounding
-cannot determine incidence

Question 20

ecological studies

Answer 20

-analytic or descriptive
-compares exposure across populations/groups not individuals
-observational
-no assigned exposure

Question 21

ecological fallacy is what

Answer 21

error made when information about groups of people is used to make inferences about individuals

Question 22

cohort study

Answer 22

-observational
-analytical
-comparison group
-exposure first then outcome
-prospective or retrospective
-follow up
-incidence of the outcome in the exposed group is compared to the incidence of the outcome in the group who were not

Question 23

prospective cohort study and an example

Answer 23

compares something different between groups in present time and the changes/differences in the future

example:
groups receiving an income supplement and groups that aren’t. where do they end up in the future?

Question 24

retrospective cohort study

Answer 24

look at an exposure group and non exposure group from the past and see if they reach outcome

Question 25

advantages of cohort studies 6

Answer 25

• ethical rct replacement
  -can examine multiple outcomes
  -association between exposure and disease
  -measures disease incidence in both groups
  -good for prognostic studies

Question 26

disadvantages of cohort studies 3

Answer 26

-prospective can be lengthy and costly
-reterospective: cheaper and easier but potential issues with bias (recall) and need a good record
-consideration of confounding

Question 27

case control studies

Answer 27

-observational
-analytic
-compare 2 groups, one with the outcome of interest (case) and another without (control)
-retrospective
-compare exposure history
-outcome first work back to find the exposure

Question 28

case control studies works in what time frames?

Answer 28

research in reverse.

present subjects with or without outcome and look back to see which risk factors have been exposed to

Question 29

advantages of case control studies 6

Answer 29

-quick and inexpensive
-suitable for rare disease
-possible to evaluate large number of potential causes/risk factors
-better for researching causality than cross sectional studies
-good where there is a long latency period

Question 30

disadvantages of case control studies 7

Answer 30

-association, not causation
-requires representation samples of cases and controls
-selection of appropriate controls can be difficult
-not suitable for rare exposures
-can only study one outcome
-selection and recall bias
-cannot calculate prevalence or incidence

Question 31

difference between case control study and cohort

Answer 31

cohort studies always start with exposure/cause and arrives at outcome

cause/ exposure: smoker/non smoker - outcome: cancer/no cancer

case control always starts with the outcome then arrives at exposure/cause
outcome: cancer/no cancer - cause/exposure: smoker / non smoker

Question 32

randomized controlled trial

Answer 32

-special type of cohort study
-examines cause- effect relationship between predictor and outcome variables
-at least two groups involved (experimental group and control group)
-randomisation ensures groups are similar as possible at start of stud
-experimental, intervened on.
-from present -different groups are exposed to different things and followed for outcomes
-prospective

Question 33

advantages of RCT

Answer 33

-gold standard in establishing cause and effect
-suitable to study more than one intervention

Question 34

disadvantages of RCT 3

Answer 34

-epensive/time consuming
-ethically complex
-hard to use info in real life due to the level of control

Question 35

flowchart of study designs