1 class 8 choosing measures to pretest, creating a questionnaire and questionnaire guide, methods...
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Class 8
Choosing Measures to Pretest, Creating a Questionnaire and Questionnaire Guide, Methods for
Pretesting Measures
November 9, 2006
Anita L. Stewart Institute for Health & Aging
University of California, San Francisco
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Basic Steps in Selecting Appropriate Measures
1. Specify context 2. Define concept for your study3. Identify and review potential measures for
a) conceptual and psychometric adequacyb) practicality and acceptabilityc) translation available if needed
4. Select best candidates5. Pretest selected measures in your target population6. Choose best ones based on pretest results OR7. Adapt if necessary to address problems
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Overview of Class 8
Choosing measures for pretesting Creating a questionnaire and a guide to
measures in your questionnaire Methods for pretesting measures
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4. Select Best Candidate Measures of Your Concept to Pretest
Select best measures for all concepts in your conceptual framework– Preferably at least 2 measures per concept
Pay special attention to priority concepts– Outcome measures or main independent
variables
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Strategies for Selecting Best Measures
Select existing instrument in its entirety Select subscales of relevant domains from
existing instruments– only those that meet your needs
Supplement existing instrument with additional measures– core plus modules approach
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What if no “Best” Measure?
For priority concepts with inadequate measure, could select optimal measure and adapt or modify
For priority concepts with no measure, may require development of new measure
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Overview of Class 8
Choosing measures for pretesting Creating a questionnaire and a guide to
measures in your questionnaire Methods for pretesting measures
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Process of Creating Questionnaire
A. Introduction
B. Statement of confidentiality
C. Length
D. Sections, section headings to break it up
E. Order of questions, measures
F. Formatting
G. Conclusion
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Process A. Introduction
Inform respondent of purpose of overall study and of this questionnaire
Who is conducting the study Topics included Expected time to complete Assurance that participation is voluntary,
can skip any questions Specific instructions for completing
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Process B. Statement of Confidentiality
Purpose: inform respondents of extent to which their answers are protected if there are risks to confidentiality, state them
Sample Statement: “All information that would permit identification of
individuals will be regarded as strictly confidential, will be used for purposes of evaluating the study, and will not be disclosed or released for any other purposes without prior consent, except as required by law.”
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Statement of Confidentiality (cont.)
Note that this is a very high reading level Would need to simplify for lower SES
group
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Process C. Length of Questionnaire
Acceptable length depends on: Commitment of respondents to topic area Health, free time of respondents
Short forms of most measures can help For those too ill or busy to complete long
survey Minimizes bias due to systematic nonresponse
of those more ill
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Process D. Sections of Questionnaire
Break up with sections, grouped by topic (minimizes psychological burden)
Introduce new topics with– Phrases - “the next questions are about how
you’ve been feeling”
– Simple section headings, e.g.,
How You’ve Been Feeling
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Process E. Question Order
Order can affect willingness to complete survey
Begin with general questions– Easy, non-threatening, interesting, related to
purpose of study Proceed with more specific questions,
more personal and sensitive questions Conclude with demographics (least
interesting, sensitive)
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Process F. Formatting Self-Administered Questionnaires
Goal - make the tasks of reading questions, following instructions, and recording answers as easy as possible for respondents – Clear instructions for indicating their answer
– Easy to track separate questions
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Principles of Formatting
Create a lot of space on page Use very light background for best contrast Number all questions Allow sufficient space for open-ended
questions– Lines far enough apart for large script
Special issues for older adults:– Larger font size (14)– Higher contrast (black on white)
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Indicate How to Respond
Give specific instructions for answering questions, e.g.,– Circle all that apply
– Circle one number
– Put a check in the box that best represents howyou feel
If no instructions, subjects will have to figure out what to do and may not do it correctly
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Types of Formats: Horizontal
How would you rate your health in general?
(circle one number)
1 Excellent 2 Good 3 Fair 4 Poor
(easy to get confused)
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Types of Formats: Horizontal
How would you rate your health in general?
(check one box)
Excellent Good Fair Poor
(Still easy to get confused)
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Types of Formats: Vertical
(circle one number)
No, not limited at all ........... 1
Yes, limited a little .......….. 2
Yes, limited a lot ...........…. 3
During the past 4 weeks, did your healthlimit you in walking one block..
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Types of Formats: Matrix (circle one number)
How often during thepast 4 weeks did No, not Yes, Yes,your health limit limited limited limitedyou in ... at all a little a lot
Walking one block 1 2 3
Walking several blocks 1 2 3
Climbing 1 flight of stairs 1 2 3
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Types of Formats: Matrix with Boxes
(Check one box on each row)How often during thepast 4 weeks did No, not Yes, Yes,your health limit limited limited limitedyou in ... at all a little a lot
Walking one block � � �Walking several blocks � � �Climbing 1 flight of stairs � � �
Easier to administer, but harder for data entry
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Process G. Conclude Questionnaire
Add a brief thank you for completing the questionnaire (for their time and effort)
If questionnaire is to be mailed back, include instructions for mailing– Always include a pre-stamped, preaddressed
return envelope
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Sample Questionnaires
See sample questionnaires– (sample formats)
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Questionnaire Guide: Organization of Survey Content Identifies purpose of each measure in the
survey (questionnaire)– Describes source of data, time points– Describes the number of scales for each
measure Documents sources of measures and items
before you forget For modified measures, helps you know
exactly how you modified it
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See Organization of Survey Content Handout Type of variable Concept Measure Data source Data points Number of items/survey question numbers Number of scores or scales for each measure References for measure sources
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Overview of Class 8
Choosing measures for pretesting Creating a questionnaire and a guide to
measures in your questionnaire Methods for pretesting measures
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Step 5: Pretest in Target Population Pretesting essential for measures being applied
to any new population group– Especially priority measures (e.g., outcomes)
Pretest is to identify:– problems with method of administration,
respondent burden, procedures– problems with questions or response choices
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Types of Pretests
General debriefing pretest (N=10) In-depth cognitive interviewing
(N=5-10 each group) Large pretest (N=100)
– test measurement properties prior to major study
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Types of Pretests
General debriefing pretest (N=10) In-depth cognitive interviewing
(N=5-10 each group) Large pretest (N=100)
– test measurement properties prior to major study
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General Debriefing Pretest
Goal
– Identify problems with the procedures
– Estimate time needed to complete instrument
– Identify serious problems with items Procedures
– Subjects answer entire questionnaire
– At end, debrief
– Close to true task
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Debriefing Questions After Administration of Survey..
Ask respondents: Were any questions confusing? Which words were hard to understand? Which questions were difficult to answer?
caused distress? Was questionnaire too long? Confusing instructions?
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Patient Acceptance Scale
6-item scale about burden of a survey Negative affect burden
– Feeling embarrassed, upset, annoyed, uncomfortable
Questionnaire length Ease of answering questionnaire
Zimmerman M et al., Med Care, 1994;32:603-608
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Example of General Pretest to Select Best Measure of Patient Satisfaction
Compared 4 questionnaires on– Response rates, missing data, completion time,
patient ratings of the questionnaire 10 evaluation items at end of questionnaire
– Clarity of questions, ease of finding an answer, questions about unimportant issues, ease of completion, too long, layout confusing, lacked important questions
Perneger TV et al., A randomized trial of four patient satisfactionquestionnaires Med Care, 2003;41(12):1343-1352
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Example of General Pretest to Select Best Measure of Patient Satisfaction
Compared 4 questionnaires on– Response rates, missing data, completion time,
patient ratings of the questionnaire 10 evaluation items at end of questionnaire
– Clarity of questions, ease of finding an answer, questions about unimportant issues, ease of completion, too long, layout confusing, lacked important questions
Perneger TV et al., A randomized trial of four patient satisfactionquestionnaires Med Care, 2003;41(12):1343-1352
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Problems with General Pretests
Respondents… often don’t understand the task. don’t want to appear as if they didn’t
understand have a hard time telling you anything was
wrong easier to say everything was fine
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Types of Pretests
General debriefing pretest (N=10) In-depth cognitive interviewing
(N=5-10 each group) Large pretest (N=100)
– test measurement properties prior to major study
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In-Depth Cognitive Interviews
Derived from social and cognitive psychology to explore processes respondents use to answer survey questions
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Cognitive Interviews Examine 4 Steps in Answering Questions
Comprehend the question (as intended) Retrieve the information
– various strategies used to access memory Judgment formation - formulate an answer
– calculate or judge the correct information Edit response - decide what to report
– is answer embarrassing, socially undesirable?
Sudman S et al., Thinking About Answers, Jossey-Bass, San Francisco, 1996
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Purpose of Cognitive Interviews
To learn .. .. if respondents understand words and phrases
as intended (meaning) .. about the process of answering the questions .. whether items are unacceptable .. about the usefulness of response choices
– whether response choices are adequate
– how they use the response choices
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Two Types of Cognitive Interviews
Think aloud interviews– Respondent asked to think aloud as they
answer question Probe interviews
– Interviewer asks specific questions to elicit how respondent answered question
– Scripted and spontaneous probing
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Think Aloud Interviews
Thorough examination of the entire thought process of creating answers
Require that respondents verbalize their thought processes as they are answering items– Hard task for most people
Mostly done at “cognitive interviewing” labs, e.g., at National Institutes of Health
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Steps in Cognitive Interview Pretesting
Identify most problematic items and develop scripted “probes”
Decide on order of administration– Probes after each question or at the end
Recruit sample for cognitive interviews Administer entire questionnaire
– Administer probe questions Summarize results
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Probe Questions to Explore Meaning
What does the word _______ mean to you?
What does the phrase ________ mean to you?
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Example:Probing the Meaning of a Phrase
I asked you about how the office staff treated you personally ….
What does the phrase “office staff” mean to you?
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Example:Probing the Meaning of a Phrase
What does the phrase “office staff” mean to you?
“the receptionist and the nurses”
“nurses and appointment people”
“the person who takes your blood pressure and the clerk in the front office”
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Example:Probing the Meaning of a Phrase
What does the phrase “office staff” mean to you?
“the receptionist and the nurses”
“nurses and appointment people”
“the person who takes your blood pressure and the clerk in the front office”
We changed the question to receptionist and appointment staff
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Types of Probes (cont.)
Retrieval– How did you remember that?
Judgment– Why did you pick that number for your answer?
Response– Do you think that most people answer this
question honestly?Collins D. Quality of Life Research 2003. 12:229-38.
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Types of Probes (cont.) Redundancy
– How is the phrase “give you advice about your diet and exercise” different from the phrase “talk to you about your diet and exercise”?
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Types of Cognitive Probes (cont.)
Cultural appropriateness and meaning:– I asked you how often doctors asked you about
your health beliefs? What does the term ‘health beliefs’ mean to you?
“.. I don’t want medicine” “.. How I feel, if I was exercising…” “.. Like religion? --not believing in
going to doctors?”
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Types of Cognitive Probes (cont.)
Cultural appropriateness and meaning:– I asked you how often doctors asked you about
your health beliefs? What does the term ‘health beliefs’ mean to you?
“.. I don’t want medicine” “.. How I feel, if I was exercising…” “.. Like religion? --not believing in
going to doctors?” We changed the question to “personal beliefs
about your health”
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Overcoming “Social Desirability” in Cognitive Interviews
Ask respondents whether they think others…– would have difficulty answering a question
– would answer the question honestly
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Example of Probe on Difficulty: CES-D Item
“During the past week, how often have you felt that you could not shake off the blues, even with help from family and friends”
Probe: Do you feel this is a question that people would or would not have difficulty understanding?– Latinos more likely than other groups to report
people would have difficulty
TP Johnson, Health Survey Research Methods, 1996
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Example:Probing the Process of Answering
I asked you _____ and you answered____. – Why did you pick this answer?– What were you thinking of when you picked this
answer? – Can you tell me what you were thinking when
you answered this way?»Can you give me some examples?
What came to mind when I asked you _____?
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Example: Use of Response Scale
Do diverse groups use the response scale in similar ways?
Re questions about cultural competence of providers– Interviewers reported that Asian respondents
who were completely satisfied did not like to use the highest score on the rating scale
CPEHN Report, 2001
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Sample Result: Use of Response Scale
In an exercise class of Samoans, instructor asked them to rate the difficulty of the exercise he just did on a 1-10 scale
They did not understand what he meant by a 1-10 scale – “Western” metric?
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Cognitive Interviewing:Example of Probing Questions
Acceptability of Questions I asked you _____.
– Did you find this question offensive?
– Was it distressing to answer this question?
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Example of Probe for Acceptability
When I asked you how often you felt discriminated against by doctors because of your race or ethnicity, you answered (read answer given).– Were you offended by this question?
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Steps in Cognitive Interview Pretesting
Identify most problematic items and develop scripted “probes”
Decide on order of administration– Probes after each question or at the end
Recruit sample for cognitive interviews Administer entire questionnaire
– Administer probe questions Summarize results
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Handouts: Examples of Probe Questions
Sample Cognitive Interview Protocol– Ron Hays and Leo Morales
Selected probes from Interpersonal Processes of Care study
Summary of NCHS working paper series on cognitive methods (website)
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Homework for Week 9
Create a short “questionnaire” of the measure, including instructions
Identify 4-5 questions in the measure you selected that might be a problem for your target population
– Phrases, length, response choices Write a “probe” question for each problem
– Include some on the meaning of a word or phrase and some on the adequacy of the response choices.
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Vogt et al.
Role of focus groups in adapting measures for diverse populations
How focus groups led to expansion and addition of constructs, confirmation of existing items, and identification of relevant quotes that could be used for new items
Appendices provide examples of construct definitions and a focus group guide
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Harris-Kojetin Reading
Example of Measure Undergoing Cognitive Testing – Consumer Assessment of Health Plans Study
(CAHPSTM) Describes extensive pretesting in
developing and refining the CAHPSTM
Provides example of good pretesting
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Pasick et al. reading
Provides examples of what can be learned through various types of pretests
Methods included– interviewing investigators and interviewers– focus groups– cognitive interview testing
Suggests that for important measures, multiple approaches to pretesting are useful
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Switzer et al. reading
From class 3 section of class binder p 405-406 – modifying measures