Part III Lecture 2

Question 1

What is responsiveness?

Answer 1

When the measure of the outcome is responsive enough to the change in exposure
- also ability to detect significant changes rather than simple random error

Question 2

Dis/Advantages of postal questionnaire?

Answer 2

ADVANTAGES

• Less expensive than personal interviews
• May include more participants
• Feasible for wide geographic area
• Good for info that requires time or sensitive questions
• No interviewer bias

DISADVANTAGES

• Low response rate opens the door to selection bias
• If questions not simple/straightforward, might have errors
• Cannot be used when we need: right order, individually filled, spontaneous answers

Question 3

What are the differences in terms of dis/advantages of electronic questionnaires (vs paper)?

Answer 3

• Even less costly
• Ok for precise order
• Ok for spontaneous responses
• But lower coverage/response rate, and higher degree of selection

Question 4

Dis/Advantages of telephone interviews?

Answer 4

ADVANTAGES

• Higher response rate than with postal/electronic
• Less expensive than face-to-face (but still need to train interviewers)
• More anonymous
• May clarify unclear questions and control order of questions

DISADVANTAGES

• Cannot show images
• More missing data than in-person
• Feeling of rush due to interrupting
• Easier to terminate interview
• Not good for: important setting, collection of specimens

Question 5

Dis/Advantages of face-to-face interviews?

Answer 5

ADVANTAGES

• High response rates
• Can show stuff
• More flexible, but also can be less standardized
• Low cognitive burden for participants
• Importance of good interviewers

DISADVANTAGES

• Most expensive
• Interviewer bias, social desirability bias, recall bias
• Training of interviewers

Question 6

What bias does the use of proxy/surrogate introduce?

Answer 6

• Introduces information bias (non-diff or diff, especially if only some participants have proxies)
• Reduces selection bias (we can include incompetent participants)

Question 7

For what type of measures is proxy use good/bad?

Answer 7

Good: height, weight, etc.
Moderate: medical history, smoking history
Poor: diet

Question 8

When are diaries generally used to collect data?

Answer 8

Used to collect data prospectively on diet, use of health services, physical/sexual activity, etc.

Question 9

Dis/Advantages of diaries?

Answer 9

ADVANTAGES:
- Highly accurate for current behaviour, with high details

DISADVANTAGES:

• Only current exposure (a measure of past exposure only if highly correlated)
• Average of current behaviour is accurate only if sufficient number of days/weeks are captured
• Needs more time/skills from participants –> and motivation
• More complex to code

Question 10

Dis/Advantages of records?

Answer 10

ADVANTAGES:

• Available and representative
• Linkable to other databases
• Accuracy
• No recall bias

DISADVANTAGES:

• Not meant for research, so no control over how the information was collected and the questions
• Not standardized
• Missing data