Evidence-based medicine (EDM) began in the early 1990s and was seen as a revolutionary movement that would improve patient care. It grew to become the buzz-word for all medical and behavioral health care—make sure treatment is evidence-based! And yet, there is little evidence that EDM has achieved its aim. Health care costs have soared and there is a distinct lack of “high-quality evidence suggesting that EBM has resulted in substantial population-level health gains.”
Given that EBM firmly favours an empirical approach over expert opinion and mechanistic rationale, it is ironic that its widespread acceptance has been based on expert opinion and mechanistic reasoning, rather than EBM ‘evidence’ that it actually works.
The article from which the above critique was taken suggested that the lack of evidence for the overall benefit of EBM was a consequence of it not being implemented effectively. A cornerstone of EBM methodology—the randomized trial—has been corrupted by vested interests. The authors, Every-Palmer and Howick, defined EBM as “the conscientious and judicious use of current best evidence in conjunction with clinical expertise and patient values to guide health care decisions.” They singled out the field of psychiatry for specific concern, where “the problems with corruption of randomized trials are dramatic.”
Most of the medical psychiatric evidence base has been funded by the pharmaceutical industry, often without the relationships being disclosed. “Between two-thirds and three-quarters of all randomized trials in major journals have been shown to be industry funded.” One of the consequences of this has been publication bias: positive results are published; negative results are not. The best current estimate is that half of all completed clinical trials have never been published in academic journals. Some trials are never registered.
There is also evidence that industry-funded studies exaggerate the treatment effects in favor of the product preferred by their sponsor. One study reviewed industry-funded studies of atypical antipsychotics and found that 90% of the trials showed superiority of the sponsor’s drug. The studies had been designed “in a way that would virtually guarantee the favoured drug would ‘win.’”
Among their recommendations, Every-Palmer and Howick suggested that all clinical trials should be registered and reported. There needs to be more investment in independent research. Evidence-ranking schemes also need to be modified to account for industry bias. These suggestions would be helpful corrections for the corruption of the randomized trial methodology, but what if there are additional problems? For example, merely correcting problems with the misuse of randomized trials would not address concerns related to clinical expertise or patient values.
If current medical science is reaching its limits with some complex illnesses, as Every-Palmer and Howick said was one possibility for the lack of progress with EBM, then further gains will be hard to come by. This would seem to be true with mental illness and addiction, which are diagnosed with the Diagnostic and Statistical Manual (DSM), 5th edition. DSM diagnoses are consensus-based decisions about clusters of symptoms and do not have any objective laboratory measure. Thomas Insel, the Director of the National Institute of Mental Health (NIMH), said that diagnosis with the DSM was equivalent to “creating diagnostic systems based on the nature of chest pain or the quality of fever.”
A further compounding error could be when the role of clinical judgment is neutralized as a result of an overreliance upon the trump of scientific—real or imagined—evidence. Kiene and Kiene noted how the reputation of clinical judgment in medicine has undergone a “substantial transformation” over the last century with the rise of modern research methodology. “A primary mission [in medical progress] therefore became ‘to guard against any use of judgement’, and it was executed through clinical trials.”
Giovanni Fava pointed to the increasing crisis in psychiatric research and practice because “Psychopathology and clinical judgment are often discarded as non-scientific and obsolete methods.” He noted how the concept of evidence-based medicine has achieved widespread endorsement in all areas of clinical medicine, including psychiatry. But randomized trials were not intended to answer questions about the treatment of individual patients. “The results may show comparative efficacy of treatment for an average randomized patient, but not for pertinent subgroups formed by characteristics such as severity of symptoms, comorbidity and other clinical nuances.”
An aura of authority is given to collections of “best available evidence”, which can in turn lead to major abuses that produce “inappropriate guidelines” for clinical practice. The risk is especially serious as a result of the substantial financial conflicts of interest in medical societies and with the authors of the medical guidelines for clinical practice within those societies.
Special interest groups are thus using evidence-based medicine to enforce treatment through guidelines, advocating what can be subsumed under the German language term of “ Leitkultur ”, which connotes the cultural superiority of a culture, with policies of compulsory cultural assimilation. In psychiatry, such process has achieved strong prescribing connotations, with a resulting neglect of psychosocial treatments.
Given the existing crisis within psychiatry, especially with the questionable validity and reliability of diagnosis within the DSM, evidence-based treatment guidelines that were developed and disseminated within such a culture require radical revision or should be used with extreme caution. The evidence for their efficacy is lacking.
