INTERVIEWING SKILLS Acknowledgement: The majority of this information was abstracted from the training program Foodborne Illness Investigations March 1999 developed by the FDA s State Training Branch. I. Task List A. Prior to Interviews Identify specific interviewing objectives. Identify the persons to be interviewed. Select the questionnaire content and format (open-ended vs. closed-ended). Assign and prepare staff who will be interviewing. B. During Interviews Establish rapport with the individuals being interviewed. Ask questions as written if closed-ended questionnaire is being used. Review form before ending interview to ensure fully complete. Ask if individuals have unanswered questions or additional information to share. Thank them for their cooperation. C. After the interview Turn in questionnaires to be reviewed (quality control). Enter information into database as soon as possible. Keep track of who has been interviewed and who is interviewing.
II. Task List Related Information A. Prior to Interviews Identify specific interviewing objectives What information must be collected? The source of the illness Means of transmission. How to gather it? Target questions to the greatest degree possible so that relevant information is gathered the first time. Minimize the number of repeat contacts. Identify the persons to be interviewed. Attempt to understand the individuals involved. Remember that the goal is to get the facts as they occurred without biasing the results. Consider what language and format are appropriate to avoid creating intimidating atmosphere; Demographic factors include age, gender, background, and occupation. Involvement in the incident that could create roadblocks. Potential for defensiveness Angry about becoming ill (food preparation) Confused about their involvement Investigators typically need to gather information from diverse people; Physicians and health care providers, People at the function (both ills and wells), Owner of the establishment, and Cooks, kitchen crew, and wait staff. Someone may try to work against you. Document the information provided. Check with other sources to verify accuracy and check consistency.
Select the questionnaire content and format (open-ended vs. closed-ended). Core information that should be gathered during every outbreak investigation includes; Demographic data (e.g., age, sex, address, phone number). Food history of typically 72 hours. Recognize that this may need to be altered for certain foodborne pathogens (E. coli 0157:H7, Listeria momcytogenes, Hepatitis A). Foods consumed and specific locations of facilities where foods were consumed or purchased (include address whenever possible). Times of consumption. Potential extent of exposure (who else consumed the food?). Gather contact information. For commercially processed foods: Purchase date(s). Product descriptions. Medical history related to outbreak to verify the diagnosis. Signs, symptoms, duration. Duration of symptoms typically longer for bacterial than viral. Need to define diarrhea: >3 loose stools in a 24 hour period is a well accepted standard. Medical care/diagnostics Who did they see? Were they given a diagnosis? If so, what was the diagnosis? Were stool samples collected? Other specimens? Availability of food or clinical samples (e.g., did diners take food home?) Potential for non-foodborne routes of transmission (remember last meal bias). Travel Pets or other animal contact Water (drinking or recreational) Illnesses in household or other close contacts (possible person-to-person transmission) Other Open-ended questions Can be time consuming. Allow person to respond in multiple words. Encourage person to use own words to tell their story. May be more difficult to analyze statistically than yes-no questions. Typically used for initial interviewing before many specifics are known.
Closed-ended questions Closed-ended questions usually have just one answer option. Typically used to gather specific information that can be used for casedefinitions, hypothesis development and testing. Potentially restrictive and leading. Example: "Did you eat the chicken salad? Can be used if a response to an open-ended question does not address what the issue (fill in any voids). Example: "What were the foods that you ate?" Then follow up with: "Did you consume any other foods or drinks?" Obtain list of foods served by caterer or restaurant. Cannot rely on the individual s memory alone. Get a list of the items served. Generic Forms Typically used for small outbreaks or early in an investigation before specifics are known. Different generic forms are used by various disciplines at present Routine unconfirmed illnesses: complete IAMFES Form C 1-2 - recommended for use by Environmental Health. Routine laboratory confirmed infections: MDCH Enteric Illness Report - required for use by communicable disease staff to report to MDCH. Use of same forms throughout the entire investigation increases consistency. Customized outbreak questionnaires Consult an epidemiologist or experienced investigator to ensure questions are unbiased. Avoid leading questions or "double barrel" questions which are difficult to answer with a yes or no response. Example: "Did you clean and sanitize the cutting board?" has two parts; Did you clean it? and Did you sanitize it? Advantages of using a structured questionnaire: Identifies more specifically the information to be gathered, increasing consistency and completeness. Decreases number of follow up contacts to fill in data gaps. Development of questionnaire by team members builds consensus regarding what information is important. How the questions are asked and the order of questions can affect the answers.
Hints on food history questions Assess the individual s ability to recall food consumption Persons with excellent memories can provide important clues People may not remember fast food meals (example: drive through) as well as meals consumed at sit-down restaurants. Persons who work as food handlers may not have eaten meals at their place of work, but still may have consumed foods from work. Obtaining a menu or accurate list of the items served is important, as it will aid in assisting persons remember accurately what they consumed. Misclassification bias results when investigators inaccurately assess which foods were consumed, resulting in failure to detect a valid association between illness and consumption of a particular food. Word questions differently for weddings/buffets vs. restaurants. Restaurants - People typically remember what they ordered. Buffets Food items generally not labeled and questions need to clearly describe each food (importance of obtaining a complete list of all foods served). Have an other food category on questionnaires. Allows respondents to indicate consumption of a food not previously known to have been served; Check master food list (menu) to verify that it is complete and accurate. Ask clarifying questions to ensure that they are not using a different name for a food on the list (e.g., crab salad and macaroni salad may be the same). Recognize the potential for last meal bias which is difficult to rule out when investigating isolated incidents. Identifying food preferences can be helpful when individual is not certain what they ate (e.g., individuals state they definitely would not have eaten buffet items containing pineapple). Assess probability that foods were consumed (definite, probable, possible, definitely not). Have individual identify what they typically would eat for the meal (e.g., cereal or bagel for breakfast). Identifying food categories that they would likely eat or definitely would not eat can provide important clues to help rule in or rule out consumption of certain foods. It may sometimes be appropriate to ask where people sat at an event or their place in line at a buffet style party. Assess person-to-person transmission at a sick table.
Assign and prepare staff who will be interviewing Minimize roadblocks to effective two-way communication; Noise and distractions, Lack of trust, Fear of losing job, Not in persons interest to communicate the truth, and Reluctance to incriminate self or a friend. Review characteristics of effective interviewer (as needed) to create an atmosphere that is: Non judgmental Objective Sympathetic (strives to maintain confidentiality) Fair An interview is a directed and purposeful "conversation" requiring good communication skills including; Listening - Interpreting what is said correctly, and Observation - Picking up on nonverbal cues. Assign adequate numbers of interviewers and arrange work schedules to allow interviewing at times most likely to yield the best results: Make it convenient for the person you're interviewing (interviewing is not 9-5 business). Remember that the public is not obligated to communicate with you. Maintain good will so individuals are willing to cooperate. Balance quality of information gathered vs. quantity of interviews that must be completed. When conducting face-to-face interviews; Maintain eye contact. Being sensitive to "signals" that may indicate stress or uneasiness. Body language, Failure to make eye contact, Signs of stress in the voice, and Pauses and inconsistent information.
Adjust your approach and try to regain a comfort level with the person. Allow for differences in personal interviewing styles. Individuality itself is not a problem. Some people naturally come on strong. Others are more passive. Do not let style effect objectivity. Be aware of preconceived opinions and your own bias. Maintain an unhurried pace during the interview. Too direct and rushed questioning may be interpreted as the third degree. Focus on the person being interviewed. Seek to understand: Where other people are coming from, How they might react, and What's at stake for them. Obtain information about disease causing organisms from a current text (see listed references for examples). Familiarize all interviewers with the questionnaire that will be used. Reach agreement on format and content. Go over with the entire group of interviewers. Pilot testing is recommended. Recall bias a significant factor to overcome. Tips to increase accuracy of recall: Jog their memory by asking them to think what else they were doing during the time period. Be prepared with days and dates from that time period (e.g., community events, holidays, school vacations). Using a calendar to map out individual's activities may be helpful. Identify appropriate site(s) for interviews. This can help you get a more accurate picture of what happened. Think about the person's feelings. Avoid distractions. Privacy Prefer not to tell the world about the diarrhea Self-incrimination (avoid interviewing food workers with their supervisors present).
B. During Interviews Establish rapport with the individuals being interviewed. People do not care how much you know until they know how much you care. Emphasize that their cooperation will help find the cause(s) of the outbreak and prevent others from becoming ill. Inform them that investigators may need to re-interview them at different points in the investigation to gather additional information. The focus of questions may change. Need to confirm or clarify information already provided. Ask at the beginning Is this a convenient time for you? If not, reschedule. Be punctual, keeping appointments as promised. Begin interviews by letting people know; Who you are (name and title), Who you work for, Your purpose, and Why you need their cooperation. Example: "There've been reports of possible foodborne illness and I m investigating to find out what happened." How long the interview will take. Practice effective listening skills. Consider repeating the question and answer to be sure you both agree on what was said. Avoid leading people to provide answers they believe you want to hear Example: You didn t happen to eat the alfalfa sprouts did you? Assess the persons communication style: Action: Bottom-line just the facts. Feeling: In touch with their emotions and relationships. Creative: Needs to see the big picture and how everything ties in together. Thinking: Loves the details.
Inform individuals up front that multiple contacts may be necessary and the focus of the questions may change. Ease into the interview by starting with a few directed questions like: What is your name? Your address? Occupation? Be open and honest without divulging confidential information. Refer questions regarding medical care to a nurse or health-care provider. Ask questions as written if closed-ended questionnaire is being used. Make sure to ask questions in the order listed on the questionnaire. Questions asked in inconsistent order may collect inaccurate information. Example: Make sure to ask these questions in the following order if interested in determining the duration of illness: Were you ill? What were your symptoms? Are you still having symptoms? What symptoms are you still having? Review form before completing interview to ensure fully complete. Ask if individuals have unanswered questions or additional information to share. Questionnaires may not contain all the appropriate questions. Involved persons may have information that investigators have not previously considered. Share noteworthy or unusual findings with the team leader immediately. If for some reason you can't complete the interview: Make another appointment. Provide your name and phone number (leave card). Allow people to call you from the security of their own home.
Invite the person to contact you if they think of anything else. Thank them for their time. Thank them for their cooperation. C. After the Interview Turn in questionnaires to be reviewed (quality control). This allows for early identification of inconsistencies in: Interviewing methods. Problems with questionnaire design (example: inaccurate list of foods served). Enter information into database as soon as possible. This allows for timely: Refinement of case-definitions and working hypotheses, and Implementation of control actions. Keep track of who has been interviewed and who is interviewing. Avoid duplication. A master list is important especially if different agencies are involved.