(2004; 98 pages)
3.7 Structured interviews
Structured interviews include a number of questions in a pre-defined order. They can deal with various aspects of medicines’ provision. Either drug providers or consumers may be interviewed. The most common form of structured interview confronts the provider or consumer of drugs with hypothetical patients: e.g. what would you prescribe/use for complaint x, in patient y? Structured interviews are also used to complement observations that the researcher makes during consultations. Physicians are then asked what they prescribed, and why they chose a certain treatment.
FORM FOR THE INVENTORY OF HOUSEHOLD MEDICINE CABINETS
Name of informant:
Name of interviewer:
CONTENTS (GENERIC NAMES)
USED FOR WHICH SYMPTOMS
In EXIT INTERVIEWS, people leaving health facilities, dispensaries or private pharmacies can be asked in a structured way about the consultation, treatment and information given, and the perceived quality of care.
Consumers may be interviewed at home, in a hospital, a health centre, and at formal or informal drug outlets. Questions could cover topics such as:
• types of medicines available/being purchased
• complaints for which medicines are purchased
• prices of the medicines
• source of advice on the purchase
• treatment taken before buying drugs
• ideas about the correct use of the medicines.
Consumers can be interviewed in their home, which is where they are most likely to take the medicines. An advantage of household interviews, unlike interviews at drug outlets, is that a sample can be selected which is representative of the population in a certain area (by random sampling).
How to conduct structured interviews
In conducting the interviews the researcher uses a questionnaire as a tool. Developing a questionnaire is not an easy task. First the researcher has to clearly define the objectives of the study, and the specific research questions. Only then can appropriate questions be formulated. The following points can serve as a guideline:
• use the objectives of the study to compile a list of topics, and hypotheses
• identify the variables to be measured, and the independent variables (such as socio-economic status, age, etc.) to which the findings should be related. It is best to design the tables that are wanted as a study output, before designing the questionnaire
• use semi-structured interviews or FGDs to learn about the way in which people talk about the topics in the local language. Use this understanding when preparing questions for the questionnaire
• write the questionnaire in the local language, and translate it back to the original language to check that the content has not changed in the “translation” process
• questionnaires should be short; omit any questions that are not needed to answer the study objectives
• write guidelines for the interviewers, and pre-test the questionnaire in an area which is not where the actual research will be conducted but which has similar characteristics.
In designing and pre-testing the questionnaires the interviewers should check for each question:
1. If it is understood.
2. If the question is neutral, i.e. it avoids leading the respondent to one of the possible answers.
3. That it does not contain implicit assumptions that are not valid, for example the question “which side-effects did you experience?” assumes that side-effects occur.
4. That it is needed; maybe there are other - easier and more reliable - ways to answer the research question.
5. That it elicits answers that are sufficiently precise to meet the objectives of the research. For example, the question “which drugs did you take in the past months?” is not a useful question, because people simply cannot remember over such a long time span. The question “which drugs did you take yesterday, and the day before yesterday?” is much more reliable, as people are likely to remember what they did in the past two days quite accurately.
This checklist can serve as a guideline to prevent the most obvious mistakes. If the researchers have limited research experience, it is best to consult a social scientist with experience in quantitative surveys when constructing a questionnaire. If the data are to be processed by computer, then data-processing personnel should be asked for advice on the best way to design the questionnaire and code the responses. The extent to which the responses can be coded depends on the questions. If so-called open questions are used, then the researchers have to code the responses after conducting the interviews. In the case of closed questions, containing a pre-defined list of possible answers, then each answer can be assigned a code on the interview form. This makes data processing easier.
Finally, it is essential that the data forms are easy to use by the interviewers. Leave sufficient space for the answers.
In the small-scale surveys that are proposed in this guide, computer analysis is usually unnecessary. Because the questionnaires are short and the number of respondents are limited to around 100, the researcher can hand-tally the results. The statistics that are used are generally descriptive involving simple frequency tables and percentages.
Strengths and weaknesses of structured interviews
The strengths of structured interviews are:
• useful for large-scale studies with many respondents who represent the population
• they can be used to describe how often drug use practices occur
• findings can be compared with other studies and used to measure the impact of interventions
• can test hypothesis using statistical tests.
The weaknesses of structured interviews are:
• respondents have little control over the interview
• no data are obtained on aspects of the problem not included in questions
• the validity of the responses may be low due to an “unnatural” atmosphere in the interview.
One specific type of structured interview that has proved to be of great use in studying community medicines use is the weekly illness recall.