Family Practice Vol. 16, No. 1, 1-3
© Oxford University Press 1999
Editorial |
Individual case studies in primary health care
Department of Psychology, Ridley Building, University of Newcastle-upon-Tyne NE1 7RU, UK. e-mail: bruce.charlton{at} ncl.ac.uk
Charlton BG. Editorial: Individual case studies in primary health care. Family Practice 1999; 16: 1–3.
Introduction
The individual study case is probably the most neglected of clinical research methods. Yet case studies come in many shapes and sizes, with many objectives and methodologies ranging from the philosophical, through the accidental, to the formally scientific.1 This article is intended to demonstrate that there is a case study for almost every purpose and temperament.
Sacks and the single case study— moral reflection
Oliver Sacks is perhaps the greatest current exponent of the case study as ‘moral philosophy’. Although Sacks includes a great deal of scientific background and clinical detail in his accounts of neurological patients, the accounts are primarily aimed at a general audience. Their purpose would implicitly appear to be moral reflection rather than medical education or scientific research.
Sacks' cases are typically people who have strange neurological conditions with profound implications for their identity and sense of self. For example, in the eponymous story from The Man who Mistook his Wife for a Hat, we are invited into the world of a man with visual agnosia.2 We are drawn to consider what it must be like to perceive, but not to comprehend: to be aware of visual stimuli but so profoundly to misinterpret them as to mistake a woman's head for a hat. In The Lost Mariner from the same volume, Sacks tells the story of a sailor suffering from Korsakoff's psychosis who lives in an eternal present; and speculates on whether such a man can be said to have a ‘soul’ or whether he is morally ‘lost’.
To elicit the moral dimension from such stories a genuine, long-term human relationship seems to be vital. It is noticeable that Sacks' best case studies are of those patients he has known for the longest, and returned to again and again—when he presents ‘celebrity’ patients, as in his more recent work, he fails to rise above the level of competent journalism.
The lesson for family practitioners contemplating the construction of ‘stories of sickness’ would appear to be two-fold. One prerequisite is literary ability, of course (something Sacks has in spades). But equally important is a long-term, sympathetic concern: a desire to learn. Because when it comes to the practice of moral philosophy, there are no experts.
Strange but true—the hypothesis-generating case study
Another type of case study concerns the ‘strange but true’ patient. The most famous example is perhaps Phineas Gage, the nineteenth century railway ‘navvie’ whose frontal lobes were partially destroyed by an iron rod following an accidental explosion.3 Perhaps the most remarkable thing about Gage was that, despite extensive damage, most of his intellectual faculties remained intact—only his social skills and judgment were severely affected. The case provided powerful evidence that brain functions were anatomically localized.
More modern examples come from the work of John Marshall. John Marshall was co-author of one of the seminal papers on the case study method,4 and has gone on to use several forms of the method with great success—particularly in his collaborations with Peter Halligan. One of the strangest is the man who apparently claimed to have three arms.5 Through repeated discussion and questioning, the patient's subjective experience of illness was elucidated such that this claim became psychologically and neurologically intelligible.
Marshall and Halligan's general approach in this and other work has been to document their chosen case as completely as possible, using all the usual modes of clinical, laboratory and psychological testing. They supplement this ‘objective’ documentation with repeated, in-depth and wide-ranging semi-structured interviews (a semi-structured interview has a pre-determined list of topics to be covered, but this can be done in an order and manner sensitive to the progress of the discussion). Interviews are tape-recorded, and results are expressed in the form of a summary supplemented by exerpted verbatim quotations.
There are considerable possibilities for modifying this approach for use in primary health care. GPs have the potential advantage of a long-term, pre-disease relationship with the patient, and may be able to supplement detailed current knowledge with a rich background of past history and contextual information on home and family.
Clinical discovery
The individual case study, or a series of individual case studies, has an unrivalled track-record as being a tool of primary discovery. In psychiatry, most of the major treatments—such as chlorpromazine, the monoamine oxidase inhibitors and ECT for depression—were discovered when clinicians carefully observed the effects of management in ‘open’ testing conditions.6 The crucial prerequisite here is to be an informed, experienced and self-critical investigator with a particular kind of clinical skill.
Roland Kuhn, discoverer of the antidepressant activity of imipramine (the first tricylic), describes the process:7 ‘I have never used "controlled double blind studies" with "placebos", "standardized rating scales" or the statistical treatment of records of large numbers of patients. Instead I examined each patient individually every day, often on several occasions, and questioned him or her again and again. Many of the patients were also under the observation of my assistants and nursing staff and I always regarded their proposals and criticism seriously.’ The consequence was that Kuhn discovered the paradigmatic antidepressant before it was even known that such drugs existed—and he was able to describe almost all of the features of the drug that have since been confirmed by other researchers using more controlled and apparently ‘objective’ study methods.
It is striking that GPs have made so few discoveries of this kind. However, there is no reason in principle why they should not start doing so—given sufficient knowledge and clinical skill, combined with the opportunity and will to set time aside for the purpose.
Serendipity
Serendipitous case studies are unplanned and retrospective: they involve the process whereby an implicit hypothesis is tested by the sheer chance of a clinician noticing a case which unexpectedly throws light on it—it is noticing the significantly unexpected, and what counts as ‘significant’ can only be established by contextual knowledge of the relevant science and medicine.1 Indeed, until he sees the case, the clinician may have been unaware that he held the theory which is being challenged.
Serendipity is the term to describe those ‘happy accidents’ that sometimes occur—the observation where a single instance suddenly creates a whole area of insight. Alexander Fleming's legendary accidental observation of the bactericidal effect of penicillin is a famous scientific example of that process. But it is not just a matter of ‘chance’: Louis Pasteur noted that chance ‘favours the prepared mind’, and the crucial factor in the serendipitous case study is mental preparation.
When a researcher's mind has been well stocked with relevant scientific and clinical knowledge, this may be taken to constitute a detailed (although probably largely unconscious) framework of expectation. This framework leads to predictions concerned with patients and their illnesses or diseases. When a ‘happy accident’ occurs, these predictions are overthrown: the accident serves to modify the framework of expectation in an important and interesting way. In a nutshell, only the prepared mind can detect significant novelty; this is the lesson for GPs who aspire to emulate Pasteur.
The planned case study
The planned case study is simply one of the methods of formal science—its particular value for medicine is that many potentially valuable experiments are unethical, so it is necessary to rely upon the ‘natural experiments’ of disease and trauma in order to understand human functioning. The scientific scope of individual case studies is quite simple: case studies can be used to test any theory which has implications for individual cases.
Although case studies have recently acquired an unmerited reputation as being anecdotal, unscientific and intrinsically inferior to group studies, this reputation is based upon ignorance rather than insight. Indeed reflex hostility seems largely confined to those who misunderstand and overestimate the role of statistics in science.8 While clinical case studies are barred from some medical journals, psychological case studies of patients with unusual brain lesions are frequently published in the most prestigious ‘pure’ scientific journals such as Science and Nature.9,10
The nature of formal case studies involves two crucial methodological principles.1 First, developing and deriving a scientific theory of sufficient precision to have implications for individual cases. Secondly, to test this model against ‘pure’ cases in which its implications may be studied without interference from relevant potentially interfering factors.
The case study method is unusually clinician-friendly as a method of doing formal research (a worked example is given in reference 1). Clinicians have unique advantages in formal case-finding because ‘screening’ for suitable subjects can often be incorporated into clinical practice, and clinicians have the opportunity to maintain ‘surveillance’ for serendipitous observations.
For instance, a clinician might have a hunch; do some thinking, reading and talking; develop a general theory leading to a number of testable predictions in the form of hypotheses; create specific operational criteria for selecting suitable pure cases; and then simply remain alert for suitable pure cases to test the hypotheses upon. Cases might emerge as a part of routine clinical practice, without any specific or systematic effort at case finding, the clinician merely needing to be alert for the right kind of patient walking through the door.
Conclusion
It is a major advantage of case studies that most of the hard thinking and theorizing can be done away from the clinic, prior to meeting potential subjects, and free from the time-constraints of practice. Even formal case studies need not interfere with the performance of routine work. However, like any research approach, case study methods should not be used in isolation, but should instead be integrated with other scientific methods and sources of evidence. Typically, a successful case study will point toward further studies employing other research methods.1
Case studies come in flavours to suit all palates, from those of the soft-boiled contemplative philosopher to the hard-nosed gung-ho scientist: but their potential in family practice remains untapped. Worthwhile research is never easy, but the case study is probably better suited to the logistical constraints of primary health care than most other methodologies.
The field is wide open. GPs may yet prove themselves to be the ultimate exponents of the difficult but fascinating craft of the individual case study.
References
1 Charlton BG, Walston F. Individual case studies in clinical research. J Eval Clin Pract 1998; 4: 147–155.[Medline]
2 Sacks O. The Man who Mistook his Wife for a Hat. London: Picador, 1986.
3 Damasio A. Déscartes' Error: Emotion, Reason, and the Human Brain. New York: Grosset, 1994.
4 Marshall JC, Newcombe F. Putative problems and pure progress in neuropsychological single-case studies. J Clin Neuropsych 1984; 6: 65–70.
5
Halligan PW, Marshall JC, Wade DT. Three arms: a case study of supernumerary phantom limb after right hemisphere stroke. J Neurol Neurosurg Psychiatr 1993; 56: 159–166.
6 Healy D. The Antidepressant Era. Cambridge, Massachusetts: Harvard University Press, 1998.
7 Healy D. The Psychopharmacologists. Vol. II. London: Altman, 1998.
8 Charlton BG. Statistical malpractice. J R Coll Physicians Lond 1996; 30: 112–114.[Web of Science][Medline]
9
Bechara A, Tranel D, Damasio H, Adolphs R, Rockland C, Damasio AR. Double dissociation of conditioning and declarative knowledge relative to the amygdala and hippocampus in humans. Science 1995; 269: 1115–1118.
10 Adolphs R, Tranel D, Damasio H, Damasio A. Impaired recognition of emotion in facial expressions following bilateral damage to the human amygdala. Nature 1994; 372: 669–672.[Medline]
CiteULike 
Connotea 
Del.icio.us What's this?
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||