HOW TO DESIGN AND VALIDATE MY PAIN QUESTIONNAIRE?

Transcription

1 DEPARTMENT <EXPERIMENTAL-CLINICAL AND HEALTH PSYCHOLOGY... > RESEARCH GROUP <.GHPLAB.. > HOW TO DESIGN AND VALIDATE MY PAIN QUESTIONNAIRE? Geert Crombez

2 SELF-REPORT INSTRUMENTS What? Outcomes: Pain, Distress, Disability Processes: Beliefs, acceptance,. Why? Key outcomes: Patient-Reported Outcomes Predictors and targets of intervention Easy to administer, and at low cost Reliable and valid

3 RELIABILITY AND VALIDITY 3

4 Reliabiliity Test-retest reliability Internal consistency Validity Content validity To what extent do items reflect contstruct Construct validity To what extent is construct measured? To what extent is research with instruments in line with hypotheses? Factor analysis, multitrait multimethod approach, structural equation modelling Criterion validity To what extent is instrument related to relevant outcomes (criterion) Concurrent validity & predictive validity Responsiveness To what extent is instrument able to assess relevant change

5 OBJECTIVES AND BOTTOM-LINE 1. Design 2. Validate 5

6 THE FIRST QUESTION WHEN YOU WANT TO DESIGN YOUR QUESTIONNAIRE Why would you? Really? 6

7 THERE IS A LOT AVAILABLE 7

8 ALSO MANY COLLABORATIVE INITIATIVES AND FREE OF CHARGE 8

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10 ALSO IN PSYCHOLOGY 10

11 1. HOW TO SELECT? What is your objective? Screening (predictive purpose) Diagnosis and psychosocial bilan (discriminative purpose) Treatment outcome (evaluative purpose) Who is your target population? Level of specificity: generic, disease, pain, Age group Other questions or caveats? Time window for responding? Last 3 months, last week? Risk factors? Stable: gender, abuse, SES Modifiable: Obstacles for recovery 11

12 VALIDITY IS NOT ABSOLUTE Valid for particular purpose in a particular group in a particular setting Personality measure not appropriate to measure treatment effects Beck Depression Inventory not appropriate to measure depressive mood in chronic pain Von Korff Grading Scale is not appropriate for Multidisciplinary Pain Centre Which type of validity depends upon purpose Screening & Diagnosis: Criterion validity Outcome research: Responsiveness, Content and Construct validity Never ending story Validation rather than validity We can t have it all Times they are a changing

13 MULTIDIMENSIONAL PAIN INVENTORY: PART 3 PARTICIPATION IN COMMON DAILY ACTIVITIES Wash dishes Mow the law Play cards or other games Work on the car Wash the car Work in the garden 13

14 2. HOW TO TRANSLATE? Ask permission to original author Maybe there are allready translations License agreement: authorized translation Use translation protocol FACIT (Functional Assessment of Chronic Illness Therapy) 14

15 FACIT TRANSLATION PROJECT PROCEDURES AND GUIDELINES Step 1: Forward translation by 2 native speakers 2 independent translations Step 2: Reconciliation by 1 other native speaker Step 3: Back translation by 1 native English speaker Step 4: Feedback by original author on backtranslation Step 5: Review by 3 bilingual speakers Step 6: Formatting and proofreading Step 7: Pilot testing with patients Cognitive interview 15

16 3. HOW TO DESIGN A QUESTIONNAIRE? Guidelines and inspiration PROMIS ( Patient Reported Outcome Measurement Information System ) Discriminant Content Validity Method (Dixon et al., 2007) Cognitive interview method 16

17 DISCRIMINANT CONTENT VALIDITY METHOD 1. Identify your contructs/components and provide clear definition Definition according theories Check with judges (experts, patients) Delphi method 2. Identify or generate items Existing or newly formulated items Ask feedback from experts or judges in the process 3. Identify judges for proper evaluation of items Experts Target population 4. Establish a scale to rate the relevance of the items for the construct 5. Test the content validity of the items To what extent does an item is relevant for measuring a construct? 6. Analyse the results 17

18 SMALL EXCERCISE 18

19 HOW MUCH ARE YOU BOTHERED BY PAINS IN YOUR LOWER BACK? Pain Disability Somatisation

20 HOW MUCH ARE YOU BOTHERED BY PAINS IN YOUR LOWER BACK? Pain Disability Somatisation (SCL-90, Symptom Check List)

21 I NEED TO CONCENTRATE ON GETTING RID OF MY PAIN Pain coping Pain-related fear Pain willingness

22 I NEED TO CONCENTRATE ON GETTING RID OF MY PAIN Pain coping Pain-related fear Pain willingness (CPAQ: Chronic Pain Acceptance Questionnaire)

23 Systematic literature review 113 empirical studies between 1989 and Communicate somatic symptoms 2. Unaccounted for by pathological findings 3. To attribute them to physcal illness 4. Seek medical help 100 % 3.4 % 0.0% 1.0%

24 HOW TO FORMULATE ITEMS? Not alone, brainstorm, take your time, identify items in literature Think about a 12 year old as target Brief sentences & simple language No double negations Acceptable and applicable in target population Unambiguous en 1-dimensional Use appropriate time window Use appropriate response scale (e.g. 7-point scale) 24

25 JUST GIVE IT A GO? Somatisation Depression Acceptance Psychological Flexibility Pain willingness Hypervigilance Coping Hypochondriasis Disability Acceptance Pain-related fear 25

26 HOW TO DESIGN A QUESTIONNAIRE Guidelines and inspiration PROMIS ( Patient Reported Outcome Measurement Information System ) Discriminant Content Validity Method (Dixon et al., 2007) Cognitive interview method 26

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28 THREE STEP TEST INTERVIEW (1) An observation step the respondent completes the questionnaire while speaking aloud what (s)he is doing or thinking; (2) A follow-up probing step the interviewer asks questions about actions or thoughts of the respondent (indicated in step one) about which the interviewer feels not fully informed; (3) A debriefing step The interviewer elicits the opinions and feelings from the respondent about the items. 28

29 DO THE EXCERCISE (0=NEVER TRUE, 6=ALWAYS TRUE) I am getting on with the business of living no matter what my level of pain is My life is going well, even though I have chronic pain It's O.K. to experience pain I don't think it is possible to decrease my basic pain level I would gladly sacrifice important things in my life to control this pain better It's not necessary for me to control my pain in order to handle my life well I can get more control over my pain by decreasing my negative and irrational thinking 29

30 3. HOW TO VALIDATE Screening: predictive purpose What is the outcome? Need for cutt-off score How good is your instrument able to predict? Sensivitity/specificity, AUC,. Guidelines for evaluating predictive instruments/studies (PROBAST) Diagnosis and pyschosocial attributes (discriminative purpose) What is your criterium for identifying individuals with the attribute/diagnosis? Depression, catastrophizing, acceptance, Need for cutt-off score or norms How good is your instrument able to differentiate? Treatment outcome (evaluative purpose) Responsiveness Need for minimally clinically important difference (Patient Global Impression of Change) How good is your instrument able to detect meaningful change? Guidelines for evaluating evaluative instruments/studies (COSMIN) 30

31 OBJECTIVES AND BOTTOM-LINE 1. Design 2. Validate 31

32 THANK YOU FOR YOUR ATTENTION 32