Week 4

Question 1

what is critical appraisal?

Answer 1

• appraises research for its strengths, limitations, and value for practice

Question 2

what is the first step in the critical appraisal of QNR

Answer 2

• determining match between the clinical question and research design
  ex. should it be QL or QN

Question 3

the critical appraisal process for QN focuses on 3 broad questions:

Answer 3

• are the results of the study valid (validity)
• what are the results? (reliability)
• will the results help me in caring for my pts ? (applicability)

Question 4

what is study bias (2)

Answer 4

• anything that distorts study findings in a systematic way arising from the methodology of the study
• something consistently occurring that could distort the outcomes & compromise the validity of the findings
  ex. instrumentation that isnt valid or reliable, or confounding or extraneous variables

Question 5

what is internal validity (3)

Answer 5

• anything that happens within the study that confounds our understanding of the relationship between the IV and DV
• what is the strength of the evidence that the IV rather than extraneous, confounding variables , or the instruments used caused the outcome
• the extent to which it is possible to make inference that the IV truly caused/influenced the DV

Question 6

what is external validity (2)

Answer 6

• what is the strength of evidence that observed relationships are generalizable across people, settings, and time?
• being able ton generalize findings to population outside of the study

Question 7

what is study validity

Answer 7

• refers to whether the study results can be believed (internal validity) and whether the results can be generalized to other settings/pt populations (external validity)

Question 8

what is instrument validity (2)

Answer 8

• refers to whether the study measurements are measuring what they are supposed to be measuring
• can serve as a threat to internal study validity

Question 9

what is study reliability (2)

Answer 9

• refers to the repeatability of the study

- if the study were repeated under the same circumstances, would the results be the same?

Question 10

what is instrument reliability

Answer 10

• refers to the consistency of the instruments

- will the instruments yield the same results under the same conditions?

Question 11

what can we ask to assess internal validity? (2)

Answer 11

• did the IV truly influence the DV?

- what competing explanation could there be for the results of the study?

Question 12

what can help control internal validity (2)

Answer 12

• be aware of confounding variables

- instrument tools

Question 13

what are 8 threats to internal validity

Answer 13

• history
• mortality
• selection
• maturation
• knowledge of who receives the intervention
• recall bias
• loss to follow up
• contamination

Question 14

describe the history threat to internal validity

Answer 14

• other events co-occurring with casual factor that could also affect outcomes
• any other event that may occur along the same time as the IV is being measured in realation to its impact on the outcome

Question 15

describe the mortality threat to internal validity

Answer 15

• differential loss of participants from different groups
• drop out of study
  = attrition bias

Question 16

describe the selection threat to internal validity

Answer 16

• ## biases arising from preexisting differences between groups being compared

Question 17

what is the single biggest threat to studies that do not use an experimental design

Answer 17

• selection

Question 18

how can selection bias be addressed/prevented? (2)

Answer 18

• randomization

- imp to test demographic differences that could impact the outcome

Question 19

describe the maturation threat to internal validity

Answer 19

• processes that result simply from the passage of time

ex. natural wound healing is expected to occur with or without intervention

Question 20

describe knowledge of who receives the intervention r/t internal validity

Answer 20

• can occur if subjects or those measuring outcomes know subject group assignment
• may cause the participants to be more motivated to help the researcher get a positive response
  = performance bias

Question 21

how can performance bias be reduced

Answer 21

• by blinding

Question 22

describe recall bias

Answer 22

• can occur when subjects are asked to recall past actions or events (such as in case-control studies)
• subjects may give answers that are socially acceptable or what they “think” is what happened (may not remember correctly)

Question 23

describe recall bias

Answer 23

• can occur when subjects are asked to recall past actions or events (such as in case-control studies)
• subjects may give answers that are socially acceptable or what they “think” is what happened (may not remember correctly)

Question 24

describe how loss to follow up can be a threat to internal validity

Answer 24

• attrition could occur due to unforeseen side effects of the intervention or burdensome data collection procedures, leading to noncomparable groups

Question 25

describe the contamination threat to internal validity

Answer 25

- can occur if intervention & control groups have interaction and info is shared, especially if the intervention is educational in nature

Question 26

how can contamination be prevented

Answer 26

- implement the intervention to 1 group at a different time period

Question 27

what is the type of bias that occurs because the subject gets better at something due to the passing of time

Answer 27

- maturation threat

Question 28

what is the testing effect

Answer 28

- occurs when you give a knowledge survey, and give it to the same individual multiple times after an education intervention - the individual then starts to learn (memorize) what the right answer is

Question 29

external validity is about...

Answer 29

- generalizability

Question 30

define generalizability

Answer 30

- the extent to which study findings can be applied to other groups & settings, and wider population that is similar to the study group - dependant on reliability and validity of study procedures

Question 31

what are some threats to external validity (2)

Answer 31

- inadequate sampling of study participants (if too small, may say theres no diff when there actyally is) - unfortunately, enhancing internal validity can have adverse effects on external validity (more controls = behavior/context more artificial)

Question 32

what are some preliminary questions to ask prior to critical appraisal of quantitative studies (7)

Answer 32

- why was the study done? - what is the sample size? - are the measurements of major variables valis and reliable? - how was the data analyzed? - were there any untoward events during the conduct of the study? - how do the results fit w previous research in the area? - what does this research mean for clinical practice?

Question 33

what are the main concerns r/t reliability of a study (2)

Answer 33

- size of the intervention's effect (effect size) | - precision in effect measurement (CI)

Question 34

what are the main concerns for the applicability of a study

Answer 34

- will the study findings help me to care for my pts?