Developing a Questionnaire

Goals Discuss asking the right questions in the right way as part of an epidemiologic study. Review the steps for creating a questionnaire and the categories of information typically collected. Review types of questions and how to properly organize them into a questionnaire.

Steps in creating a questionnaire 1. Identify the leading hypotheses about the source of the problem 2. Identify the information needed to test the hypotheses 3. Identify the information needed for logistics of the study and to examine confounding

Steps in creating a questionnaire 4. Write the questions to collect this information 5. Organize the questions into questionnaire format 6. Test the questionnaire 7. Revise the questionnaire 8. Train interviewers to administer the questionnaire

Categories of information for an epidemiologic questionnaire Identifying information Demographic information Clinical information Exposure or risk factor information Source of information

Identifying information Important for the logistics of the study Includes Respondent's name or other identifiers Contact information: address and telephone number Allows Subject identification Questionnaire updates as more information becomes available Linkage of questionnaire to other records Prevention of duplicate entry of records

Demographic information Includes items such as age, sex, education level, and location Is used to characterize the population at risk Is important in the search of potential confounders Needs to be evaluated to determine if it affects the relationship between exposure and disease

Clinical information Includes Signs and symptoms of disease Date of onset of illness Results of laboratory testing Allows To characterize the illness To decide who has the outcome of interest To chart the time course of the problem

Exposure or risk factor information Is used to test the hypotheses under investigation Is probably the major focus of the questionnaire Should be specific to the problem under investigation Often includes: The respondent’s exposure to the factor of interest The route, amount, and timing of exposure and other details of exposure (e.g., brand, distributor)

Source of the information Identifies the individual supplying the information Helps to assess validity Is the interviewee the study subject or a surrogate? Identifies the interviewer Helps to correct problems Unanswered questions, illegible handwriting, nonsensical responses, inadequately trained interviewers

Types of questions Open-ended Fill-in-the-blank Closed-ended Categorical responses Ordinal responses

Types of questions Open-ended Do not provide response choices, therefore possible responses are limitless Are useful in characterizing attitudes, beliefs, and behaviors Are usually limited to hypothesis- generating activities

Types of questions Fill-in-the-blank Do not provide response choices Require short responses (one or two words) Are used to measure a simple respondent attribute, collect a date, or quantification Require categorization and coding of responses

Types of questions Closed-ended Response choices are provided Categorical responses: categories have no particular order or inherent numerical value with respect to one another Ordinal responses: responses describe a range of choices and have a quantitative values with respect to each other.

Types of questions Closed-ended Investigator must Anticipate likely responses Present the responses as a list of mutually exclusive choices State responses clearly and concisely

Selecting the type of question Depends on: The kind of information you need Your expectations about that information During early exploration, when you know little about a problem, you will be more likely to use open-ended questions As you learn more about the problem and can anticipate responses, you will be more likely to use closed-ended questions

Writing questions Wording depends on: Knowledge of the problem Hypothesis being tested Information being collected Affected population

Wording of questions Use language respondents can understand Test translated questionnaires with native speakers and “backtranslate” to test the translation Limit each question to a single idea Word each question as precisely as possible

Wording of questions Do not phrase questions in a way that suggests a response Avoid double negatives Always include a “Don’t know” or “Refused” category option In closed-ended questions, be sure that categories cover all potential responses and are mutually exclusive

Questionnaire design Introduction Identify the sponsoring organization Explain the purpose of the study State how long the interview is likely to take and reassure the participant that their answers are confidential

Questionnaire design Length As short and focused on the hypothesis being tested as possible Try to gather additional information of interest to the investigators without compromising parsimony Logic Organize questions in a way that promotes rapport between respondent and interviewer Do not skip from topic to topic; the questionnaire should appear logically organized

Questionnaire design Layout Clearly state instructions Number questions and pages Include an identifying code for the respondent on each page Separate responses from questions Include skip patterns Ending statements Thank the respondent Provide contact information

Conclusions The first step in questionnaire development is to frame and refine the hypotheses under study and decide what information is needed to test the hypotheses. Then design the questionnaire paying careful attention to the type of question used, wording and organization.

Reference University of North Carolina at Chapel Hill School of Public Health, Department of Maternal and Child Health (2003). Data Skills Online: A Maternal and Child Health Toolbox. "Designing Questionnaires."