24. THE AFFECTS THAT INFORMATION BIAS HAS ON STUDY RESULTS

Question 1

1. What is the Fundamental Principle of Research?

Answer 1

IF YOU WANT TO INVESTIGATE ANY ASSOCIATION BETWEEN TWO FACTORS:
- you have to make sure that you first measure these
two factors accurately

Question 2

2. Where can information bias be introduced in the assessment?

Answer 2

• there can be information bias in the assessment of the
  main exposure
• there can be information bias in the assessment of the
  main outcome
• this can distort the association between them

Question 3

3. What is a more common type of information bias?

Answer 3

• the information bias resulting from the participant’s
  actions
• this is much more common than the information bias
  arising from the researcher’s actions

Question 4

4. What kind of studies does the information bias affect the most?

Answer 4

• it affects the studies that rely on self reports
• such as questionnaires

Question 5

5. When it comes to outcome assessments, what kind of measure is applied to confirm the results?

Answer 5

NB:
- outcome assessments are also known as
Measurements

IN THE OUTCOME ASSESSMENT:
- there is usually double-checking of the results

Question 6

6. What are some examples of exposures?

Answer 6

• smoking
• physical activity
• educational attainment

Question 7

7. What kind of instruments are used when we assess Exposures?

Answer 7

• the most valid and reliable instruments

Question 8

8. What should be assumed if the study relies solely on Self-Reports?

Answer 8

• there is Information Bias present to some extent
• this is known as a Measurement Error

Question 9

9. What does the presence of Information Bias result in?

Answer 9

• it always compromises the Validity of the study results
• the findings then have to be interpreted with caution

Question 10

10. What two factors should any assessment tool used in research ideally have?

Answer 10

• high validity
• high reliability

Question 11

11. Define Validity?

Answer 11

• this is the extent to which an assessment tool
  accurately measures what it is intended to measure

Question 12

12. What are 2 examples of assessment tools?

Answer 12

1. Questionnaires
2. Instruments

Question 13

13. What is the most common type of validity used in Medical research?

Answer 13

• Criterion Validity
• the results from the assessment tool of interest
  are compared to the results of an established
  assessment tool
• this is known as the Gold Standard

Question 14

14. Define Reliability?

Answer 14

• this is the overall consistency of a measure

IT FOCUSES ON:
- producing the same results when administered under
the same conditions in the same group of people
- this is known as Reproducibility
- or as Repeatability

Question 15

15. What are the 2 main types of Reliability in Medical Research?

Answer 15

1. Inter-Observer Reliability
2. Intra-Observer Reliability

Question 16

16. What is Inter-Observer Reliability?

Answer 16

• this is the degree of agreement between the results

THIS TAKES PLACE WHEN:
- two or more researchers (observers)
- administer the assessment tool
- on the same people
- under the same conditions

Question 17

17. What is Intra-Observer Reliability?

Answer 17

• this is the degree of agreement between the results

THIS TAKES PLACE WHEN:
- one researchers (observer)
- administer the assessment tool
- on two or more occasions
- in the same test population
- under the same conditions

Question 18

18. In which kinds of situations can false positive and false negative findings also arise?

Answer 18

IN SITUATIONS WHERE:
- information bias will affect the outcome of interest

Question 19

19. What happens if both the outcome and the exposure are affected by information bias?

Answer 19

• the study findings are expected to be particularly
  biased
• this is known as Erroneous

Question 20

20. What kind of biases can give rise to false positive and negative findings?

Answer 20

• all kinds of biases
• including Selection Bias
• including Random Errors

Question 21

21. What is Internal Validity?

Answer 21

• this is when the findings of a study
• were not due to any of the 3 sources of error

THE CONCLUSIONS REACHED:
- are likely to be correct for the circumstances of that
particular study

Question 22

22. What is External Validity?

Answer 22

• this is when the findings cannot be generalised to
  other circumstances

EG:
- the findings for a small group of a particular study
- CANNOT be expanded and extrapolated to the
whole population

Question 23

23. What should a person be aware of when they are reading a study?

Answer 23

• the potential biases
• these have an affect on the conclusion

A PERSON SHOULD BE ABLE TO PREDICT:
- what kind of effect a given bias would be expected to
have on the estimate

Question 24

24. What should never be compromised in the goal of generlisation?

Answer 24

• the Internal Validity of the study

AN INVALID ANSWER:
- cannot be generalised