The ethos of evidence-based practice is a simple one; it involves the application of best practice and the best use of resources. From its rise in the UK in the early 1990s, it has spread to become a global phenomenon and is now the foundation of UK health policy (Reynolds 2000). It has led to the creation of the National Institute for Health and Clinical Excellence (NICE), an independent body responsible for providing guidance on the promotion of good health and the treatment of ill health. This guidance aims to achieve consistency across health services, ensuring they are up-to-date and that they provide good value to health consumers. Sometimes politically sensitive, the sad matter of fact is that the publicly funded health services do not have endless reserves to draw upon and so resources must be used as best as possible, based on the evidence available. This is why, if CAM interventions like hypnotherapy are to be further integrated into the NHS, the need for high-quality research evidence must be met.

It is not just health providers and consumers that want the evidence to be widely available but also practitioners. Doctors, nurses and therapists, most of whom were drawn to their discipline with a desire to help, need confirmation that their actions are having a positive effect on the patient. Indeed, many CAM training courses now provide a programme of research within their syllabus which may include awareness of what the evidence says, how to find it and on the research process itself.

The House of Lords Science and Technology Report (2000) identified the lack of high-quality CAM research available and recommended that work be done to ensure that such practices be exposed to the same level of scientific rigour as conventional medicine. The report classified different therapies into three groups and placed hypnotherapy in Group 2 alongside practices like massage, aromatherapy and meditation. While satisfied that therapies in this category provide comfort and can help to complement medical treatments, the report nonetheless acknowledges the lack of a scientific basis from where they are practiced. It further recommends that structures for regulation and education are strengthened and that the evidence base is developed to underpin practice.

REASONS FOR ENGAGING IN RESEARCH

The idea of conducting a research project may seem a daunting one for a hypnotherapist. Essentially, however, research is simply the acquisition of knowledge. This can be obtained through a variety of means:

Tradition – ‘this is the way that it has always been done’

Expert opinion – listening to the teachings of accepted experts in their fields and the wisdom they have gained through experience. This could include editorials from respected figures such as Ericksson and Hilgard

Trial and error – practitioners reflecting on their practice, what worked and what did not and adapting for the next time

Historical analysis – examining a range of sources to provide a history of the development of practice and philosophy in a given field

Science – applying a logical and systematic framework to the measurement and observation of a phenomenon.

A therapist’s belief that hypnotherapy works may come from observing changes in their clients, this may be a sufficient basis for their ongoing individual practice. Equally, consumers of hypnotherapy may experience the benefits and not require that it be proven scientifically to them. Anecdotal evidence can provide interesting ‘cases’ to reflect upon. Indeed, further understanding of the application and effects of hypnotherapy can be gained by analysing the processes and outcomes for one individual. Standing alone, however, these case reports are not enough to widen the scope of practice for hypnotherapy. Ozturk (2006) reported on the case of a woman undergoing a cholecystectomy, the removal of her gall bladder. The surgery was conducted with the patient being inducted into trance but without the use of any medication. Remaining pain-free, she was conscious during the operation and was eventually discharged earlier than the accepted norm. While a case like this fires the imagination, it does not provide enough evidence to justify replacing general anaesthesia with hypnosis in similar cases. Science demands that studies are easily replicated and it may be difficult to reproduce the conditions that were in place in the previous example. The next patient may have low hypnotic susceptibility or may experience a spontaneous emergence from trance. In either case, the resulting effects may be dramatic and potentially devastating.

The aforementioned case study cited by Ozturk (2006) illustrates the need to identify variables involved in treatment, to measure them, control them and to ascertain the effects that they have on the treatment as a whole. Until quantified, the effect of variables on treatment outcomes is unknown. Examples of such variables include hypnotic susceptibility, the rapport between therapist and client, length of treatment, suggestions used and the context in which hypnotherapy is employed.

AREAS FOR RESEARCH

As mentioned earlier, the primary question that research into hypnotherapy should answer is ‘does it work’? Delving deeper, other questions quickly come to the fore:

When does it work?

Who does it work with?

How does it work?

Does it work better than existing treatments?

Does it enhance existing treatments?

Is it simply a placebo effect?

It is easy to see that no one study can possibly answer all the questions posed. An enthusiastic hypnotherapist or potential researcher may want to ‘prove’ that hypnotherapy works in one fell swoop; not only is that impractical but it is impossible. Not only is hypnotherapy a complex intervention, but the demographic differences (diagnosis, reasons for attending, expectations, etc.) among the patients who use it will also vary widely. The budding researcher needs to identify potential areas of interest (Box 4.1), to refine the question that they want to answer, to plan the most appropriate way they can answer it and, most importantly, to ensure that their question has not been answered satisfactorily by someone else. It would be a waste of time, effort and money to conduct a study if there already existed one of sufficient quality that showed significant effects. However, if a previous study had been conducted and the question posed had not been answered definitively, then a follow-up study would be feasible.

HIERARCHY OF EVIDENCE

With so many varied options when deciding on a particular research design, it is worthwhile to give the following brief synopsis of the two categories that they fall into.

QUANTITATIVE STUDIES

Quantitative studies follow the traditional, scientific method that involves employing a set of processes to obtain information. Grounded in positivist philosophy, the quantitative researcher might believe that an absolute reality exists beyond human perception and that this reality can be measured. The results of a quantitative design will often be reduced to a numerical form and be analysed using statistical procedures to ascertain whether or not a relationship exists in reality. Strict adherence to pre-specified procedures and objectivity are not just seen as desirable in such a study, they are a necessity. Qualitative researchers are interested in the human experience and attempt to explore it directly. In this naturalistic philosophy, reality is not seen as an immutable fact but rather that multiple realities exist, mentally constructed by the individual. The belief inherent in this school of thought is that a human being is too complex to be boiled down to a set of numbers and that the different dimensions of an individual’s experience can be described and understood.

Randomized controlled trial (RCT) is seen as the gold standard in determining the effectiveness of a given treatment. It is seen as ‘true’ experimental research, attempting to translate laboratory conditions to the larger world. Participants are randomly allocated to different groups, exposed to an intervention and then the results are measured. The inclusion of a control group provides a benchmark for the intervention to be tested against and members of the control group could be exposed to an alternative treatment or to no treatment. Variables that are known or suspected to affect the outcome are called confounders and they are controlled as much as possible so that the results only represent the effects of the intervention used. Ideally, an RCT would be double-blinded, i.e. neither researcher nor subject would know which intervention has been provided. In practice, this is only possible for drug trials, where the subject would be unaware whether the tablet they have taken is the active treatment or a placebo pill. In CAM research, this is impossible; it would be hard to imagine that someone would be unaware of whether they were receiving hypnotherapy or massage as part of a research trial. It is possible, however, for a researcher to blind themselves to the allocation of subjects within a trial and this is referred to as a single-blinded trial. Quasi-experimental designs encompass most of the features of the RCT but not all. It may be that there is no control group or no random allocation and so this lack of precision is why such designs are secondary to the RCT.

QUALITATIVE STUDIES

Qualitative studies are seen as more person-centred and attempt to grasp the essence of what has transpired, from the perspective of the patient. Phenomenology is a tradition in qualitative research, founded by Husserl and Heidegger that lends itself well to investigating CAM interventions like hypnotherapy. Used a great deal in the field of psychology, it focuses on the meaning of people’s lived experiences. Broadly speaking, it would involve interviewing participants after receiving a hypnotherapy session, looking to answer questions regarding what they experienced during treatment, how they felt about it and how their perception of the focus of their treatment had been affected. Qualitative researchers see the subjective nature of their work as its strength. They believe the value that an individual derives from a therapy can affect the way they feel about themselves and the way they live their lives. It would be difficult for an RCT to quantify, observe and measure such concepts.

Box 4.2 outlines the accepted hierarchy of evidence within the medical sciences, adapted from Sackett et al (2000), which forms a component of NHS research and development policy. It is easy to see that quantitative methodologies dominate the classification of acceptable evidence and thus the research priorities to affect change in service provision. Historically, clinicians have been interested in whether or not a treatment works and whether the effect can be measured. And so there exists a potential conflict as hypnotherapists may be more interested in how their clients feel about the treatment and how it has affected the way they live their lives. Such questions naturally draw themselves toward a qualitative design and although results may be compelling, parts of the medical establishment may well consider them substandard when compared with the results of a well-designed RCT.

BOX 4.2 Hierarchy of evidence

High quality