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Questionnaire Design

K AlpersC Campese, P McKeown, V Bremer, V Prikazsky

EPIET Introductory Course Lazareto, Menorca

6 October 2011

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What is a questionnaire?

• A tool for data collection

• A series of written questions

in a fixed, rational order

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A well designed questionnaire

• Good appearance (easy for the eye)

• Short and simple

• Relevant and logical

⇒ High response⇒ Easier to collect

to summarizeto analyse

• Minimises potential sources of bias

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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

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How to reduce bias

• Structured questionnaire • Ensure high response rate• Random choice of interview partners • Training of interviewers

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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

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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

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Types of Questionnaires

• Interviewer-administered– face to face

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Types of Questionnaires

• Interviewer-administered– face to face – telephone

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Types of Questionnaires

• Interviewer-administered– face to face – telephone

• Self-administered– by post

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Types of Questionnaires

• Interviewer-administered– face to face – telephone

• Self-administered– by post – Email– Internet– Social Networks

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Self-administered questionnaire• Advantages• cheap and easy to administer

– preserves confidentiality– completed at respondent's convenience– not influenced by interviewer

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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

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Interviewer-administered questionnaire

• Advantages– participation of illiterate people

– clarification of ambiguities

– quick answers

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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

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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

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Study protocol and questionnaire

Definition of objectives

List of variables to collect

Analysis plan

Study protocol

Design questions

Control and reading

Pilot test

questionnaire

questions must relate to objectives

collect appropriate information for analyses

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Use existing questionnaires

• As an inspiration• Don´t need to re-invent the wheel• Have been tested

• BUT: adapt to present situation!

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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

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Questionnaire needs to be adapted to study population

• Know the respondents– language– education– occupation – ethnic group– sensitive issues

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Structure of a questionnaire

1 Identification

2 Interview introduction

3 Instructions on how to answer

4 Questions

5 Conclusion

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ARZTFRAGEBOGEN Aktenzeichen:____________ Name, Vorname: _____________________ Geb.: ___.___._____

Masern-Ausbruch Nordfriesland Juni 2001 Dr. Gerard Krause Abt. Infektionsepidemiologie Robert Koch-Institut Seestrasse 10 13353 Berlin

Vom Befrager einzutragen: - Datum der Befragung: ___.___._____ - Initialen des Befragers (Vor-+ Nachname): ___ ___ - Name des Arztes: ________________________________

Guten Tag, mein Name ist ___ (bitte Namen nennen)___.

Ich bin Mitarbeiter im Kreisgesundheitsamt in Husum

oder Als Mitarbeiter des Robert Koch-Institutes unterstütze ich das Kreisgesundheitsamt Husum.

Wir verzeichnen derzeit im Landkreis Nordfriesland seit Anfang September 2005 eine ungewöhnliche Häufung von Masernerkrankungen. Wir möchten uns zunächst herzlich dafür bedanken, dass Sie uns

Ihren Patienten ___(Name des Falles wie in Kopfzeile)___, geboren am __(Datum wie in Kopfzeile)__,

als Masernfall gemeldet haben. Wir führen derzeit eine epidemiologische Untersuchung durch um diese Masernhäufung eindämmen zu können. Das Erfassen von Masernkomplikationen ist hier besonders wichtig. Um den von Ihnen gemeldeten Fall korrekt einordnen zu können, möchten wir noch kurz einzelne Informationen abklären. 1. Hatte Ihr Patient eines der mehrere der folgenden Symptome? Generalisierter Hautausschlag > 3 Tage: (1) Ja* (2) Nein (3) Unbekannt * Wenn ja: Wann begann der Hautauschlag?

(4) Datum genau bekannt: ___.___.2005 (5) Datum nicht genau bekannt: Auschlag begann zwischen ___.___.2005 und ___.___.2005. 2. Welche der folgenden Labornachweise liegen Ihnen zu diesem Patienten vor?

(Mehrfachnennungen möglich)

(1) Virusisolierung (2) Nukleinsäurenachweis (PCR) (3) IgM (4) IgG mit 4-fachem Titeranstieg (5) Antikörpernachweis mit 4-fachem Titeranstieg

3. War Ihr Patient gegen Masern geimpft? (bitte eine Angabe pro empfohlene Impfung)

Erste Masernimpfung:

Zweite Masernimpfung: Dritte Masernimpfung:

(1) Nein (2) Ja* (nicht dokumentiert) (3) Ja* (Impfausweis)

(1) Nein (2) Ja* (nicht dokumentiert) (3) Ja* (Impfausweis)

(1) Nein (2) Ja* (nicht dokumentiert) (3) Ja* (Impfausweis)

1 - Identification

• On first page– Return address– Study title

• On all pages– Identifyer– Page numbers

• Data protection: Identifiers kept separately from names

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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

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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 .....

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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

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4 - Questions

1. Content

2. Order

3. Format

4. Coding

5. Pitfalls

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4.1 - Content of questions

• Clear focus on research question

– avoid sidetracking

– avoid unnecessary information

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4.2 - Question order

• 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?

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Starting questions

– “Door-opener”– Simple– Closed format – Relevant to main subject– Non-offending– Neither demographic nor personal questions

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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”

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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

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Be accurate8 – 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

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Be objective10 - 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

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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

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Two main question formats

• Closed format forced choiceYes Always No Sometimes Don’t know Never

• Open format free text12 – What did you do to avoid being stung by jellyfish? Please describe : __________________________________________________________________________________

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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

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Disadvantages of open questions

• interviewer bias

• time-consuming

• coding problems

• difficult to analyse

• difficult to compare groups

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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

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Disadvantages of closed questions

• restricted number of possible answers• Possible loss of additional information

Compromise– insert field

“others,

if yes specify : __________”

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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

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14 - Which of the following beaches have you visited during your stay in Menorca?

Lazareto beach Cala’n Porter Rafalet Macarella Sa Mesquida

Closed questions: Checklist

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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

Checklist

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Rating scale

15 – How often did you see jellyfish during the past weeks?

Always Sometimes Seldom Never

Mornings Lunchtime Evenings

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Rating scaleNumerical16 - How severe was your pain after you were

stung? (please circle)

1 2 3 4 5 6 7 Not painful at all Very painful

Analogue17- How severe is your pain (put the tick on the line)

0 10

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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

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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 3Mahón 4

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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

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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

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5 - Conclusion

• Don’t forget to thank the interviewed persons

• Tell them when the results will be available and where

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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 ?

We are still in a very early phase of our investigation. Would you agree to be contacted again in case further questions arise?

In some outbreak investigations you might want to add:

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Presentation and layout

• Clear and consistent • adequate space to answer

– large font size– appropriate page breaks

• avoid • messy layouts• too many and fancy logos

• printing questionnaire on coloured paper may help

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Pilot your questionnaire!

• Pilot with a group of people

-> similar to your target subjects

• Highlight problems before starting– Misunderstandings– Look for alternative wording– Final polishing

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Summary

A well designed questionnaire:

• collects appropriate data

-> to answer your research question

• minimises potential sources of bias

-> increases the validity of the replies

• Will much more likely be completed