Evidence-based treatment (EBT) has become a hot topic in the field of eating disorders as well as healthcare in general. EBT is defined as interventions, treatments or psychotherapeutic techniques that have been shown to produce therapeutic change when studied in controlled research trials.

While the purpose of this article is not to be critical of research or devalue its importance in developing and providing quality care, I do believe it is important for those unfamiliar with research methods to understand what some of the limitations are so that EBTs related to eating disorders can be viewed in a more balanced versus idealized context.

An unfortunate misinterpretation of EBTs is occurring in the field of eating disorders. Because EBTs are supported by results derived from experiments, some clinicians and advocacy groups have concluded and are promoting that interventions that are evidence based are the only interventions that should be used in clinical practice. An example of this is Family Based Therapy for adolescents. Just as it is true that the most expert clinician cannot guarantee his/her treatment will result in a patient recovering from an eating disorder, it is also true that an EBT cannot make that guarantee either simply because it produced a change when studied under controlled conditions.

There is nothing magical about an EBT. It only means a particular intervention has been used with a group of research participants and when it is compared to another group who received no treatment or a neutral treatment, it has better results than the no or neutral treatment group(s). Many good treatments have not been studied under the rigors of empirical research, but that does not mean they are not effective or should never be used in practice.

When considering the value of an EBT, I think it is important to understand some of the well-documented challenges of conducting research and then applying the results to clinical practice. Research studies often have inclusion and exclusion criteria that determine what participants get accepted into a study. This is different than in clinical practice where patients are usually not thoroughly evaluated to determine whether a therapist will see them or not. Typically, a patient makes an appointment, then the assessment process begins.

A known criticism of research studies is that the participants accepted into clinical trials based on the inclusion/exclusion criteria have less severe disorders and fewer co-occurring conditions. For example, subjects may be included in a study if they only have bulimia, but subjects with bulimia, depression and a substance use disorder would be excluded. Therefore, it can be debated whether a treatment shown to be effective in a study will be effective in clinical practice where more complicated cases are treated. In other words, whether EBTs are generalizable to clinical practice is an issue that researchers and clinicians continually grapple with.

Another common criticism of research studies is whether results that are found to be “statistically significant” (this is of major importance to researchers and for research to be published) translates to interventions that will actually improve the functioning of patients. Statistical significance determined by analysis of the data collected on the intervention does not automatically mean the intervention will result in notable changes for patients. Conclusions about the effectiveness of an intervention cannot be made solely on whether statistical significance is achieved.

An important aspect in research is the ability to replicate the studies that produce favorable results in support of the effectiveness of a treatment intervention. A treatment becomes an EBT when the measures used to evaluate its effectiveness have an expected effect, e.g., the treatment “works.” But even when studies are replicated, the measures that show change in one study are not necessarily the same measures that show a change in the other studies attempting to replicate the results.

So, an EBT can show it is effective but, when replicated, may show effectiveness on the same measures, different measures or may show it is not effective. This does not mean EBTs have questionable merit. It just means research results should not be idealized or blindly accepted as the only viable treatment intervention.

These few points related to research limitations are just a sampling of common challenges to show that even EBTs need to be constructively evaluated by practitioners who are trained and experienced in research methodology. For more information on research methods in psychology, go to http://www.sparknotes.com/psychology/psych101/researchmethods/.

Another concept in the evidence based arena is Evidence-Based Practice in Psychology (EBPP). The American Psychological Association defines this as:

“The integration of the best available research with clinical practice in the context of patient characteristics, culture and preferences” and “the purpose of EBPP is to promote effective psychological practice and enhance public health by applying empirically supported principles of psychological assessment, case formulation, therapeutic relationship and intervention.”

Simply stated, this means that clinicians are responsible for knowing and understanding the research, using their clinical expertise, judgment and experience and integrating that knowledge in the context of the patient’s needs, values, culture and preferences to provide the most effective treatment possible. (Other disciplines in healthcare have also defined EBP and the APA principles above are consistent with other definitions).

Neither research nor clinical practice is infallible and neither is more informed than the other. Both are essential and have contributed to the ongoing development of high quality patient care. There is no need to vilify or idealize either discipline because doing so only impedes what the profession can offer to the patients we are dedicated to helping.

For a more comprehensive evaluation of EBT and EBP, please see the following article that served as a reference for this weblog:

Kazdin, A.E. (2008). Evidence-based treatment and practice: New opportunities to bridge clinical research and practice, enhance knowledge base, and improve patient care. American Psychologist, 63, 146-159.