Practical Data Gathering
Most frequently, qualitative health researchers interview individuals. They do not try to draw their samples, as quantitative researchers do, in a way that provides a subset of the population that represents the population in a probabilistic kind of way. Rather, they frequently use what is termed a purposive procedure: they use predetermined criteria to select people to invite for the study. For example, patients attending hospital because of self‐harm (usually overdose or self‐cutting) were invited for an interview to discover their views about the care and attention that they received at the hospital Emergency Department; the researchers purposively attempted to recruit approximately equal numbers of people who had taken an overdose or cut themselves, equal numbers of males and females, and equal numbers of people attending for the first time or at a repeat attendance. Sampling in qualitative research is described in some detail in Chapter 15.
Reports of qualitative research usually describe the way in which the data were collected. Often the data are gathered through the interview of a series of individuals, although groups of people (generally termed focus groups) are also widely used. Whether it is a study with individual interviews or one engaged with groups, the researchers will generally have set out for themselves an organized way of posing questions. The structure of the questioning can be extremely loose, perhaps little more than an occasional prompt on a broadly drawn subject, through to detailed and in‐depth enquiry in an organized order of questioning.
Most often the questioning, in individual interviews or focus groups, lies somewhere between these two poles and the researcher constructs a topic guide in which there are a number of open‐ended questions arranged in an order that is not necessarily adhered to should the conversation pursue its own direction. Sometimes, the topic guide is rather more structured and the qualitative researcher may refer to it as a semi‐structured interview. The content of questions varies widely but will usually pay attention to the participants' attitudes and experiences (Figure 4.4). Topic guides are referred to in more detail in Chapter 25. Where the method is participant observation, the data are recorded in rather different ways, often using field notes – written as the observations are being made or soon afterwards (Figure 4.3).
Figure 4.4 A qualitative study involving focus groups and individual interviews.
Source: Reprinted from Plugge et al. (2008), © 2008 Royal College of General Practitioners permission conveyed through Copyright Clearance Center, Inc.
It is normal practice to make audio recordings of all of the interviews and to transcribe them: the researcher, or someone paid by the researcher, listens to the recording and types out what has been said by both parties, or by everyone in the group, verbatim. Focus groups ought to provide an extra ingredient that should enrich the data: the group process itself ought to help the participants to explore, consider, clarify, and reflect on their views and their reports of experience – with the participants each assisting the researcher in eliciting one another's responses. Whether derived from individual interviews or from focus groups, the transcribed written material becomes the basis for the analysis – discussed in Chapter 38.
CHAPTER 5 Descriptive Studies: Quantitative
Broadly speaking, quantitative research may be either observational or experimental. In the first, the researcher actively observes patients by doing things like asking questions and taking samples, but does not experiment with the patient's treatment or care. In a typical experimental study, in contrast, the researcher intervenes to ensure that some or all of a group of people receive a treatment, service, or experience.
It can be helpful to divide observational studies into two groups according to their complexity (Figure 5.1). On the one hand, descriptive observational studies ask questions like: ‘What are the clinical or biochemical characteristics of people who have rheumatoid arthritis?', ‘How common a condition is asthma?', or ‘How disabled do people become over a decade of follow‐up after a diagnosis of multiple sclerosis?' On the other hand, some observational studies compare groups to try to answer more complex questions: ‘Do people who smoke get more heart disease than those who don't smoke?' or ‘Are women who experienced venous thrombosis more likely to have been taking the oral contraceptive pill than are women who didn't sustain a thrombosis?' Studies that ask these kinds of non‐experimental (observational) questions, but which involve comparisons, are often described as analytic.
Figure 5.1 Types of research study design.
Analytic observational studies are dealt with in Chapter 6 and experimental (intervention) studies in Chapter 7. The remainder of this chapter tackles the simplest forms of quantitative observation – descriptive studies. We find it useful to subdivide descriptive studies into four types:
Case reports
Case series
Cross‐sectional studies (simple cross‐sectional studies determining, for example, how common (prevalent) a condition is; more complex cross‐sectional studies involving comparisons are dealt with under analytic research in Chapter 6)
Longitudinal studies
CASE REPORTS
Some would say that case reports are scarcely research at all. They usually take the form of an unusual clinical case that illustrates something about the cause, or the outcome of the person described that the author hopes will intrigue you. Perhaps the author's care over detail – eliciting symptoms, possible precipitants, and treatments offered – takes the case report out of the ordinary clinical arena and justifies the title of research. Research journal editors vary in their views – some publish such reports and others do not.
CASE SERIES
A respectable form of research is a description of clinical findings seen in a succession of patients who seem to display a similar condition: the case series. Something unexpected has turned up – more cases than usual of a rare disorder perhaps, or an apparent excess of some clinical sign – hence the motive for writing‐up the series of cases. For example, Figure 5.2 shows how clinicians used a case series to point to dangers of playing around on bouncy castles.
