Questionnaire Design

1. Questionnaire Design EPIET Introductory Course Lazareto, Menorca 6 October 2011 K Alpers C Campese, P McKeown, V Bremer,VPrikazsky

2. What is a questionnaire? • A tool for data collection • A series of written questions in a fixed, rational order

3. A well designed questionnaire • Good appearance (easy for the eye) • Short and simple • Relevant and logical ⇒ High response ⇒ Easier to collect to summarize to analyse • Minimises potential sources of bias

4. Bias Systematic difference in the response measurement • Recall bias • Cases more likely to remember than controls • Observer bias • Different interviewers – different interpretations • Different interpretation of similar questions • Non-response bias • telephone interviews: more females, elderly

5. How to reduce bias • Structured questionnaire • Ensure high response rate • Random choice of interview partners • Training of interviewers

6. Advantages of questionnaires • Can reach a large number of people • Relatively easy and economic • Relate directly to study question • Provide quantifiable answers • Relatively easy to analyse

7. Disadvantages of questionnaires • Provide only limited insight into a problem • the range of possible responses is limited • the question maybe misleading • Varying response • Unclear question can lead to • misunderstanding • misinterpretation • Do not allow for mistakes • must be right from the beginning • missing data hard to chase

8. Types of Questionnaires • Interviewer-administered • face to face

9. Types of Questionnaires • Interviewer-administered • face to face • telephone

10. Types of Questionnaires • Interviewer-administered • face to face • telephone • Self-administered • by post

11. Types of Questionnaires • Interviewer-administered • face to face • telephone • Self-administered • by post • Email • Internet • Social Networks

12. Self-administered questionnaire • Advantages • cheap and easy to administer • preserves confidentiality • completed at respondent's convenience • not influenced by interviewer

13. Self-administered questionnaire • Advantages • cheap and easy to administer • preserves confidentiality • completed at respondent's convenience • not influenced by interviewer • Disadvantages • low response • questions can be misunderstood • no control by interviewer • only literate persons • time delay (post) • e-mail/internet: need computer access/software

14. Interviewer-administered questionnaire • Advantages • participation of illiterate people • clarification of ambiguities • quick answers

15. Interviewer-administered questionnaire • Advantages • participation of illiterate people • clarification of ambiguities • quick answers • Disadvantages • interviewer bias • needs more staff resources • only short questionnaires possible • especially on telephone • difficult for sensitive issues

16. Before starting to design a questionnaire Write a study protocol! • define objectives • define study questions Risk factors for being stung by jellyfish at Lazareto (Menorca), October 2011 Study protocol Prepared by cohort 17 Menorca, 6 October 2011

17. Study protocol and questionnaire questionnaire Study protocol Definition of objectives Design questions questions must relate to objectives collect appropriate information for analyses Control and reading List of variables to collect Pilot test Analysis plan

18. Use existing questionnaires • As an inspiration • Don´t need to re-invent the wheel • Have been tested • BUT: adapt to present situation!

19. Questionnaires for outbreak investigations • Exploratory • Generate hypotheses • Detailed • Only some cases • Based on existing questionnaires • Open questions • Analytical study • Testing hypothesis • Focus on possible vehicles

20. Questionnaire needs to be adapted to study population • Know the respondents • language • education • occupation • ethnic group • sensitive issues

21. Structure of a questionnaire • Identification • Interview introduction • Instructions on how to answer • Questions • Conclusion

22. 1 - Identification • On first page • Return address • Study title • On all pages • Identifyer • Page numbers • Data protection: Identifiers kept separately from names

23. 2 - Introduction • Covering letter/ interview introduction • Who are you / you work for • Why are you investigating • Where did you obtain the respondent’s name • How and where can you be contacted • Guarantee of confidentiality • Length of interview (be honest) ⇒ Usefulness of study should be clear to all respondents

24. Example of introduction • Good morning , My name is ..... , I work for …….. You may have been already informed that a survey on risk factors for being stung by a jellyfish will be done this week in Mahon. This study has been approved by the national ethical committee. Only anonymized data will be analysed. You have been randomly selected to participate in this study. Your participation is voluntary. The interview will take about 10 minutes. I will start with the first question .....

25. 3 - Instructions • Minimise potential sources of bias • Guide for Interviewers • Guide for Respondents in self-administered questionnaires • Which questions can be skipped => where to jump to • Selection of multiple answers possible • Use different fonts (e.g. bold or italics) Example: I will ask you a few questions about your contacts with jellyfish. You will answer by yes or no If no, go to question 27

26. 4 - Questions • Content • Order • Format • Coding • Pitfalls

27. 4.1 - Content of questions • Clear focus on research question • avoid sidetracking • avoid unnecessary information

28. 4.2 - Questionorder • Decide on the order of items/questions • easy  difficult • general  particular • factual  abstract • Group questions by topic • Be aware of ordering effects • Don’t put the most important items last • Where to place sensitive questions?

29. Starting questions • “Door-opener” • Simple • Closed format • Relevant to main subject • Non-offending • Neither demographic nor personal questions

30. 4.3 - Format of questions • Adjust to responding audience • professionals vs. public • middle class vs. prisoners • Keep sentences simple and short • Define key words (“fully vaccinated”) • Remember options • “don’t know” • “don’t want to answer”

31. Ask one thing at a time 7 - Do you like to go swimming and do you mind to be stung by jellyfish?  Yes  No • Ask for one information at a time • Answer options • Mutually exclusive and exhaustive • Vertical order of answer options

32. Be accurate 8 – What is the jellyfish situation?  Good  Bad Versus 8 - How often did you see jellyfish during the last week?  Once  Twice  Three times or more  Never • Don´t know

33. Be objective 10 - Do you agree that jellyfish are annoying? Yes No versus 10 - According to you, jellyfish in Lazareto are… not at all a public health problem not a major public health problem a potential public health problem an important public health problem  no opinion/don´t know

34. Be simple 11- Did you see more than an average of 33 jellyfish/m2 salt water surface on more than 3 occasions that you went swimming in the morning last week?  Yes  No versus 11- Have you seen jellyfish on more than 3 mornings last week?  Yes  No  Don´t know

35. Two main question formats • Closed format  forced choice Yes  Always  No  Sometimes  Don’t know  Never  • Open format  free text 12 – What did you do to avoid being stung by jellyfish? Please describe :__________________________________________________________________________________

36. Advantages of open questions • not directive • detailed and unexpected answers possible • > allow exploration of issues to generate hypotheses • useful for exploring knowledge and attitudes • qualitative research • focus groups • trawling questionnaires

37. Disadvantages of open questions • interviewer bias • time-consuming • coding problems • difficult to analyse • difficult to compare groups

38. Advantages of closed questions • Straightforward response • Simple • Quick • Less discrimination against less verbally expressive people • Easy to code, record, analyse • Easy to compare • Easy to report

39. Disadvantages of closed questions • restricted number of possible answers • Possible loss of additional information Compromise • insert field “others, if yes specify : __________”

40. Examples for closed questions 2 - What is your age in years? ___ years 3 - How long have you stayed at Lazareto? ___ days 4 - What is your sex (gender)?  Male Female 5 - Did you go swimming on 4 October 2010? Yes  No Don’t know

41. Closed questions: Checklist 14 - Which of the following beaches have you visited during your stay in Menorca? Lazareto beach • Cala’n Porter • Rafalet • Macarella • Sa Mesquida

42. Checklist 14 - Which of the following beaches have you visited during your stay in Menorca? Lazareto beach  Yes  No  Don´t know Cala’n Porter  Yes  No  Don´t know Rafalet  Yes  No  Don´t know Macarella  Yes  No  Don´t know Sa Mesquida  Yes  No  Don´t know

43. Rating scale 15 – How often did you see jellyfish during the past weeks? Always Sometimes Seldom Never Mornings     Lunchtime     Evenings    

44. Rating scale Numerical 16 - How severe was your pain after you were stung? (please circle) 1 2 3 4 5 6 7 Not painful at all Very painful Analogue 17- How severe is your pain (put the tick on the line) 0 10

45. Likert Scale • Rensis Likert, 1903-1981 • Psychometric scale • Five (or more) ordered response levels 18 – Jellyfish also have the right to swim in the Mediterranean sea  I strongly disagree  I disagree  I neither agree or disagree  I agree  I strongly agree

46. 4.4 - Coding • Answers can be pre-coded • Quicker and easier data entry • Examples: Male  1 Ill  1 Female  0 Not ill  0 Don’t know  9 Don’t know  9 Lazareto beach  1 Harbour  2 Es Castel  3 Mahón  4

47. 4.5 - Avoid pitfalls • jargon/abbreviations/slang 21- Should jellyfish victims receive a PEP? (post exposure prophylaxis) • not mutually exclusive options 22 - What is your age ? 16-20  20-25  25-30  35-40

48. Avoid…. • Leading questions 23 - Do you think we should forbid EPIET-fellows to go swimming in the mornings? • Making the questionnaire too long • Typographical / spelling errors

49. 5 - Conclusion • Don’t forget to thank the interviewed persons • Tell them when the results will be available and where

50. Example of conclusion This is the end of the interview. Thanks for answering this questionnaire. The result of this study will be available on the ECDC website in six weeks. Do you have any others questions you wish to ask ? In some outbreak investigations you might want to add: We are still in a very early phase of our investigation. Would you agree to be contacted again in case further questions arise?